Science (Semester 1) Flashcards
What are atoms made up of?
Matter
Draw a diagram of an atom.
CARBON ATOM: 6 protons + 6 neutrons in nucleus 6 electrons spread across two rings 2 in first ring 4 in second
What is a scientific theory?
a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation
How can theories be revised?
Theories are revised gradually as scientists find improvements to the theory and ‘build’ upon it.
How can theories be disproved?
Theories can be disproved by experimental results contrary to a theory’s predictions.
Discuss the atomic theory proposed by Dalton.
Dalton’s atomic theory was based on experimentation and first-hand examination. This made his theory the first scientific theory.
Summarise Dalton’s atomic theory of matter
- All matter is composed of atoms, which are indivisible and indestructible
- All atoms of an element are identical, but different elements have atoms of differing size and mass
- All compounds are formed by combinations of atoms in defined ratios.
- Chemical reactions result in the rearrangement of atoms in the reactant and product compounds
Recall some of the early models of the atom.
- Democritus’s atomic theory
- Dalton’s atomic theory of matter
- Thomson’s plum pudding model
- Rutherford model
Discuss Thomson’s Plum Pudding model of the atom.
- Atom composed of electrons
- Electrons surrounded by a ‘soup’ of positive charge to balance electron’s negative charge
- Electron arranged in rotating rings
Describe Rutherford’s gold foil experiment.
- Alpha particles with large kineticenergies were shot towards a thin foil of gold
- A ‘ring’ detector was set up around the gold foil to detect the alpha particles and where they scattered
- Most of the alpha particles passed through, but others were deflected at small angles or REFLECTED BACK AT THE SOURCE.
- This indicated a strong central positive charge.
Describe the gold foil experiment’s implications for the structure of the atom.
- Disproved Plum Pudding model
- Revealed that atom was mostly empty space
- Strong central positive charge in nucleus, which has majority of mass
- Electrons moved around in space around nucleus
- Thus, new planetary model was developed.
Discuss Rutherford’s gold foil experimental setup.
- A radioactive source rich in positively charged heavy alpha particles was inside a cube shaped thick lead box with a narrow opening
- The narrow opening confined the alpha particles into a beam
- A thin gold foil was set up away from the radioactive source (which would be bombarded by the alpha particles)
- A circular florescent detector was set up around the gold foil - screen coated with zinc sulphide flashed when alpha particles hit it
How were the results of the gold foil experiment interpreted?
- Most of the alpha particles passed through the foil undeflected: Atom mostly empty space
- Some alpha particles deflect by small angles: Strong positive charge in nucleus
- Small fraction of alpha particles reflected back: Nucleus has most of mass
Why did Rutherford propose the existence of neutrons?
- Atomic number of atom usually above half its atomic mass
- However, nuclei with 2x charge had at least double the mass that was expected from the protons contained (DISPARITY)
Why was it difficult for Rutherford to prove the existence of neutrons?
Neutrons hold no charge, thus they could not be detected by electric/magnetic fields.
What charge does a proton hold?
Positive
What charge does an electron hold?
Negative
What charge does a neutron hold?
None
Calculate the numbers of protons, neutrons and electrons in an atom given its mass and atomic numbers.
Atomic number = no. of protons = no. of electrons
Mass number = no. of protons + no. of neutrons
Neutrons = atomic number - mass number
Explain the relative atomic mass scale.
weighted average of masses of isotopes in a naturally occurring element relative to mass of carbon-12 atom (standard)
How are atomic numbers determined?
Atomic number = no. of protons = no. of electrons
How are mass numbers determined?
Mass number = no. of protons + no. of neutrons
What are isotopes?
different forms of an atom that vary in mass and number of neutrons
How are isotopes similar and different?
- Isotopes (of the same element) share similar physical/chemical properties
- Isotopes differ in their number of neutrons and thus atomic mass
- Some isotopes are unstable, and will undergo radioactive decay to become another element.
How does the abundance of isotopes lead to the calculation of relative atomic mass?
- Most elements have more than one naturally occurring isotope
- Thus, the average mass of the isotopes of an element is used.
- Relative atomic mass is listed on the periodic table.
What are electron shells?
a grouping of electrons in an orbit surrounding the nucleus of an atom
- The more energy electrons have, the further their orbit. The closer, the most stable.
- The valence shell determines the element’s chemical / bonding properties
List the maximum number of electrons the four electron shells can hold.
First shell: 2
Second shell: 8
Third shell: 8 (up to calcium), 18 (above calcium)
Fourth shell: 32
Do you draw the electrons in pairs?
Yup.
What are the implications of flame tests?
- When atoms of an element are excited (flame) and electrons jump energy levels (and back), a photon is emitted (light) that releases a certain amount of energy of a particular wavelength
- The bigger the jump, the more energy released.
- The wavelength is represented by a coloured line in the emission spectrum.
- Each element has an unique spectrum, as the possible values of energy for the electrons present are different for each element.
- Thus, the flame test allows us to observe the colours emitted by an excited element, and thus distinguish between different elements.
Explain the colours in flame tests in terms of subatomic structure and relate colours to energy gap between electron shells.
- Electrons jump energy levels inside an atom when excited. The distance between the ground and excited state is called the energy gap.
- Photons with a high frequency (e.g. blue light) have a large energy gap.
- Photos with a low frequency (e.g. red light) have a low energy gap.
What colour do photons with a high frequency usually take on?
Blue light
What colour do photons with a low frequency usually take on?
Red light
What is alpha radiation?
- Alpha particles similar to helium nucleus (2 protons, 2 neutrons)
- Positive charge of +2
- Low penetration power due to large size
- Alpha decay occurs when radioisotope’s nucleus has excess protons
- Alpha particle emitted to keep neutron/proton balance
- Mass of 4 Daltons
What charge does alpha radiation hold?
+2
When does alpha decay occur?
When the nucleus of a radioisotope has excess protons, and an alpha particle is emitted to keep neutron/proton balance
What is the mass of an alpha particle?
4 Daltons
What is beta radiation?
- An electron
- Charge of -1
- Smaller mass gives it high penetration power
- Beta decay occurs when radioisotope has excess protons/neutrons
- Neutron decays into proton and electron - proton emitted, but electron kept, increasing atomic number by one, thus changing element
What charge does beta radiation hold?
-1
When does beta decay occur?
- Beta decay occurs when radioisotope has excess protons/neutrons
- Neutron decays into proton and electron - proton emitted, but electron kept, increasing atomic number by one, thus changing element
How is a beta particle produced?
When a neutron decays into a proton and electron, and the proton is emitted but electron kept
What is gamma radiation?
- A stream of high-frequency electromagnetic waves with NO MASS/CHARGE
- Highest penetration power - can penetrate most common substances
- Gamma decay occurs when radioisotope’s nucleus energy level is too high after emission of alpha/beta particle
- Gamma ray photon emitted in order to decay to lower energy state
When does gamma decay occur?
Gamma decay occurs when the energy level of a radioisotope’s nucleus, after the emission of an alpha/beta particle is too high.
A gamma ray photon is emitted in order to decay to a lower energy state.
What does the gamma ray photon release?
Electromagnetic radiation.
What is half-life?
the time taken for the radioactivity of a specified radioisotope to fall to half its original value
How can radiation be used in carbon dating?
- Carbon-14 is a radioisotope which appears in all living organisms.
- After an organism dies, it stops taking in carbon-14 and the carbon-14 contained at the time of death decays and thus the radioactivity of the material decreases.
- The approximate time since the organism died can be worked out by measuring the amount of carbon-14 left in its remains compared to the amount in living organisms.
How is radiation used in nuclear power?
Nuclear reactions are used in some countries as the source to generate some/most of their electricity.
How is radiation used in medicine?
Radioactive substances are used in research, diagnosis and treatment. Brachytherapy (radiation therapy inside the body) is used as a treatment for cancer.
Explain nuclear power.
Nuclear power relies on nuclear fission to make energy.
What is nuclear fission?
Nuclear fission happens when a neutron hits an uranium atom and splits it, releasing energy in the form of heat and radiation. This releases more neutrons, which hit more uranium atoms and the process repeats. This is called a nuclear chain reaction.
How does a nuclear power plant work?
- Nuclear energy is converted into heat in a nuclear reactor.
- The heat is transferred to water, turning it into steam.
- The steam drives a turbine, which drives electricity generators to convert the mechanical energy into electricity.
- The electricity flows out to a power grid.
Evaluate the dangers of radiation.
Radiation can damage the cells in your body by ionising atoms and changing the properties of them - free radicals are released in the process, which can damage DNA.
List the uses of radiation in medicine.
- Diagnosis
- X-rays, scans, injection of radioactive material for nuclear medicine imaging (tracers)
- Treatment
- Brachytherapy
- Placement of radioactive substance near tumour kills cancerous cells
- Radiation therapy
- External beam of radiation
- Swallowing, or injection of radioactive materials
- Brachytherapy
Understand the concept of the Big Bang theory.
- The universe started with a small singularity, then inflated to the current cosmos.
- In the first second after the universe began, a 10 billion degree cosmos existed that included neutrons, protons, electrons, anti-electrons, photons and neutrinos.
- As the Universe cooled, the neutrons decayed into protons and electrons, or combined with protons to make deuterium.
- Eventually, the Universe reached a temperature cool enough where free electrons combined with nuclei to create neutral atoms. This made the Universe transparent.
- It was opaque before, because the free electrons would have caused light (photons) to scatter.
What is the nuclear genesis theory?
the process that creates new atomic nuclei from pre-existing nucleons, primarily protons and neutrons
How is the periodic table organised?
- By atomic number
- Organised by periods (rows) and groups (columns)
- The period an element is in indicates the number of electron shells in it.
- The group an element is indicates the number of valence electrons.
- Periods are organised by weight, increasing from left to right and top to bottom
- Groups are organised by similar characteristics
What does the period an element is in indicate?
The number of electron shells in it
What does the group an element is in indicate?
The number of electrons in its valence shell.
How was the current periodic table developed?
Pre 1869, the periodic table was organised according to metals and non-metals, and chemical symbols were added - a system of atomic weights was also developed.
In 1869, Mendeleev organised the 63 elements into order of atomic weight and into groups with similar properties. From there on, noble gases were discovered by refrigeration, the elements were sorted by atomic number (using X-rays) and nuclear processes were used to identify nine transuranium elements.
What are the properties of metals?
- Lustrous (shiny)
- Can conduct heat and electricity
- Malleable (able to be shaped)
- Ductile (able to be drawn out into thin wire)
What are the properties of non-metals?
- Dull / not lustrous
- Poor conduction of heat / electricity
- Non-malleable (brittle)
- Non-ductile
Differentiate between metals and non-metals
Metals
- Lustrous (shiny) - Can conduct heat and electricity - Malleable (able to be shaped) - Ductile (able to be drawn out into thin wire)
Non-metals
- Dull / not lustrous - Poor conduction of heat / electricity - Non-malleable (brittle) - Non-ductile
Where are the alkali metals located in the periodic table?
Group 1
Where are the alkali earth metals located in the periodic table?
Group 2
Where are the transition metals located in the periodic table?
Groups 3-12
Where are the metalloids located in the periodic table?
Border stair-stepped line
Where are the halogens located in the periodic table?
Group 17
Where are the noble gases located in the periodic table?
Group 18
Recall the name, symbol, colour, features and uses of at least three common metals
Aluminium: Al, shiny/silver, low density/weight + super malleability + good thermal and electrical conductivity, used to make foil wrap and silver paper
Iron: Fe, silvery grey, easily malleable + durable + rusts easily, commonly used metal - magnetic
Gold: Au, shiny yellow, extremely malleable/ductile + good conductor of electricity/heat + dense, used in electronics and jewellery and as money
Copper: Cu, shiny brown, resistant to corrosion + anti-bacterial properties + super malleable + second greatest thermal/electrical conductivity, used in electrical wires and water pipes
What is the symbol for aluminium?
Al
What is the symbol for iron?
Fe
What is the symbol for Gold?
Au
What is the symbol for copper?
Cu
What are the features of aluminium?
Low density/weight
Superior malleability
Good thermal and electrical conductivity
What are the features of iron?
Easily malleable
Durable
Rusts easily
What are the features of gold?
Extremely malleable/ductile
Good conductor of electricity/heat
Dense
What are the features of copper?
Corrosion-resistant
Anti-bacterial properties
Super malleability
Second greatest thermal/electrical conductivity
What is aluminium used for?
Used to make foil wrap and silver paper
What is iron used for?
Commonly used metal - magnetic.
What is copper used for?
Used in electrical wires and water pipes
What is gold used for?
Used in electronics and jewellery and as money
Recall the name, symbol and special properties of at least two metalloids and their location on the periodic table.
Metalloids are located on the stepped border between metals and non-metals.
Boron / B / Good conductor at high temperatures + compounds used (e.g detergents)
Silicon / Si / Used as semiconductor + Brittle + Inactive at room temp
Arsenic / As / Tarnishes when in contact with air + Oxidizes when heated + Used to give color to flame in pyrotechnics
Recall the name, symbol and characteristic of at least two non-metals
Carbon / C / Highest melting point of all elements + can exist in several allotropes + has highest thermal conductivity in form of diamond + in form of graphite, one of softest substances
Fluorine / F / Most reactive element + Lightest halogen
+ Reacts violently with water to produce oxygen and hydrofluoric acid
Chlorine / Cl / Toxic gas that irritates skin, eyes and respiratory system + Sharp smell + Powerful bleaching, oxidising and disinfecting agent
Xenon / Xe / Colorless and odorless + Inert towards most chemicals
What is the order of activity for selected metals?
- The elements towards the bottom left of the periodic table are the metals that are the most active/reactive.
- The rate increases as you go down the column, because the elements become more active as they become more metallic.
Explain the link between periodic table groups and the number of electrons in valence shells
The number of electrons in the valence shells of elements in the group is the same as the group number.
Why do ions form?
Ions form when atoms gain / lose valence electrons in order to have full valence shells.
Recall three properties of ionic compounds.
- Hard and brittle crystals at room temp
- High melting/boiling points
- Conductive in liquid form
Explain why metals are good conductors.
- The structure of metal consists of a lattice of positive ions (cations) in a sea of free/delocalised electrons.
- This allows the electrons to move freely throughout the structure, and allows them to conduct electricity/heat.
- Example: when electric voltage is applied, the electrons carry an electrical charge and an electric field within the metal triggers the movement of electrons from the ‘negative’ to the ‘positive.
- Example: when metal is heated, the electrons carry kinetic energy and travel through the structure, slowly covering the whole lattice with heat.
Recall three properties of covalent compounds.
- Low melting points and boiling points
- Do not exhibit electrical conductivity in all forms
- May exist as solid, liquid and gas at room temp
List at least four common metals found in sea water and identify the source of one of them.
- Sodium (dissolves into water as sodium ions)
- Magnesium
- Potassium
- Gold
- Bromine
What is the source of sodium in sea water?
Sodium on the ocean floor dissolves into the water in the form of sodium ions (Na+).
Relate the position of elements in the periodic table to their properties
The group that an element is located in determines the number of valence electrons it has, which determines its chemical and bonding properties.
What’s the difference between distillation and reverse osmosis for producing fresh water from sea water?
- Distillation: the seawater is drawn into the plant and boiled to evaporate the water, leaving the salts behind. The evaporated water is cooled so it condenses into pure water.
- Reverse osmosis: Sea water is passed through membranes at high pressure, which removes a large proportion of the dissolved salts.
Evaluate desalination as a source of water
- The process of desalination consumes a huge amount of electricity.
- However, the valuable minerals extracted as by-products from the water offset some of the cost.
Identify one common non-metal found in sea water and name its source
Sulfur (or bromine)
Source: byproduct of volcanic activity. exists as sulfate ions in today’s oceans
Explain the significance of the work of Mendeleev.
- Mendeleev invented the modern periodic table.
- He organised the elements into order of atomic weight, then into groups with similar properties.
- Proposed periodic law: ‘Elements have properties that recur or repeat according to their atomic weight.’
- He also left gaps for undiscovered elements. He predicted the properties of 21 unknown or undiscovered elements.
Discuss problems associated with arranging the periodic table in order of atomic weights
Atomic weights are the average of the atomic mass of all the isotopes of an element. This doesn’t represent chemical properties and thus is not conductive to organising the periodic table.
- Contrasted by groups, which have same number as valence electrons which determine chemical and bonding properties.
Discuss advantages to using atomic numbers
Atomic numbers tell us the number of protons, which equals the number of electrons - the number of electrons in the valence shell determine the chemical and bonding properties of an element. This means the atomic number helps determine the chemical relationships between elements.
How does Mendeleev’s table differ from our modern periodic table?
Mendeleev’s periodic table was arranged in order of increasing atomic weight. There were gaps for missing elements.
What is valency?
- Valency is the combining power of an element.
- This is determined based on the number of electrons that would be added, lost or share if it reacts with other atoms.
How can the charge of ions formed from elements in groups 1-8 in the periodic table be predicted?
Find the charge by taking away 8 from the group number the ion is in.
How can you predict the valencies of elements using the periodic table?
- The valency of an atom is equal to the number of electrons in the outer shell if that number is four or less. (use group number)
- Otherwise, the valency is equal to eight minus the number of electrons in the outer shell.
How do you name an ionic compound?
cation name + (anion name with ending dropped and replaced with -ide)
Name Al2O3.
Numbers do not affect name.
First part: aluminium
second part: oxygen -> oxide
Full name = aluminium oxide
How do you name a covalent compound?
- Add prefix to element names to indicate how many atoms of each element are shown in formula
- Drop the ending of the last element, and replace it with -ide
What is the prefix that corresponds with one atom?
Mono
What is the prefix that corresponds with two atoms?
Di
What is the prefix that corresponds with three atoms?
Tri
What is the prefix that corresponds with four atoms?
Tetra
What is the prefix that corresponds with five atoms?
Penta
What is the prefix that corresponds with six atoms?
Hexa
What is the prefix that corresponds with seven atoms?
Hepta
What is the prefix that corresponds with eight atoms?
Octa
Name CO
Carbon monoxide
Name N2S3
Dinitrogen trisulfide
How do you write the formulae for simple compounds using valency?
The ones place of the group number corresponds with its valency.
The valency of an atom is equal to the number of electrons in the outer shell if that number is four or less. Otherwise, the valency is equal to eight minus the number of electrons in the outer shell.
- Write symbols of elements
- Write valency as sub-script each symbol
- Swap valencies over
- Simplify by dividing both by smaller of two numbers. If one of the numbers is one, they cannot be simplified further.
Write the formula for aluminium oxide.
- AlO
- Al3O2
- Al2O3
- FINAL = Al2O3
How do you find the valency of a polyatomic ion/radical?
- Find the charge of each atom
- Add them all together
- You’ve found the valency
What’s the difference between ionic and covalent bonding?
- Covalent bond: bond in which one or more pairs of electrons are shared by two atoms
- Ionic bond: bond in which one or more electrons from one atom are removed and attached to another atom, resulting in positive and negative ions which attract each other
How do you classify compounds into electrolytes and non-electrolytes
- Ionic compounds conduct electricity, and thus are electrolytes
- Covalent compounds do not conduct electricity because they have no free electrons / no ions, so they are non-electrolytes
What are the two components of the CNS?
- Brain
- Spinal cord
What is the CNS responsible for?
Processing and synthesising sensory input into instructions for motor output to rest of body
What is the PNS responsible for?
Connecting internal/external stimuli and CNS to allow body to respond to environment.
What does the sensory neuron do?
convert external stimuli from environment into internal stimuli
Where are the sensory neurons found?
The PNS
What does the interneuron do?
receive message from sensory neuron, process info and send response message to motor neurons
Where are the interneurons found?
The CNS, spinal cord and brain
What does the motor neuron do?
receives message from CNS and connects to effectors to carry out response
Where are motor neurons found?
The PNS
List the four main components of the human brain.
- Thalamus
- brain stem
- Cerebellum
- Hypothalamus
What does the thalamus do?
processes and carries messages for sensory information
What does the brain stem do?
controls the flow of messages between the brain and the rest of the body and basic body functions
What makes up the brain stem?
- Medulla
- Pons
- Midbrain
What is the function of the medulla?
controls automatic functions (e.g. breathing, digestive system activities)
What is the function of the pons?
Assists in some automatic functions and controls sleep and arousal
What is the function of the midbrain?
receives and processes sensory information (e.g. movement/vision)
What is the function of the cerebellum?
responsible for movement, balance and coordination
What is the function of the hypothalamus?
tiny, responsible for heart rate, body temp and sleep pattern. Also involved in hormone production - controls pituitary gland
What are the four lobes in the cerebrum?
- Frontal lobe
- Parietal lobe
- Occipital lobe
- Temporal lobe
What is the function of the frontal lobe?
processes smells, controls movement and cognitive functions (etc. emotions, speech, reasoning)
What is the function of the parietal lobe?
involved in speech & reading, manages perception of senses (etc. pressure, pain, temperature, taste) and senses location of parts of body
What is the function of the occipital lobe?
responsible for vision. Interprets visual cues, such as what we see and recognise (eg. faces and objects)
What is the function of the temporal lobe?
recognises sounds. Forms new memories (hippocampus)
Why is the spinal cord important?
The spinal cord relays information from the brain and back. It serves as a conduit for sensor input and motor output.
What are the implications of damage to the spinal cord?
If damaged, paralysis may occur - the spinal cord doesn’t heal as spinal nerves lack the ability to regenerate
How does the spinal cord contribute to reflex actions?
Controls reflex actions through local connections between neurons.
What are the components of the peripheral nervous system?
- Autonomic nervous system
- Sympathetic nervous system
- Parasympathetic nervous system
- Somatic nervous system
What is the function of the autonomic nervous system?
regulates involuntary actions such as breathing and digestion
What is the function of the somatic nervous system?
governs voluntary action and body reflexes (without brain input)
What is the function of the sympathetic nervous system?
activates “fight-or-flight” stress responses / endocrine system to produce adrenalin
What is the function of the parasympathetic nervous system?
returns body back to normal state after stress (counteracts sympathetic)
Name at least three hormones in the body.
- Testosterone
- Insulin
- Glucagon
- Antidiuretic hormone
- Progesterone
What organ does testosterone originate from?
Testes
What organ does insulin originate from?
Pancreas
What organ does glucagon originate from?
Pancreas
What organ does the antidiuretic hormone originate from?
Pituitary gland (anterior and posterior)
What organ does progesterone originate from?
The ovaries
What organ does testosterone target?
Male reproductive system, body cells
What organ does insulin target?
Liver, muscle and fat cells
What organ does glucagon target?
Liver
What organ does the antidiuretic hormone target?
Kidneys
What organ does progesterone target?
Uterus
What are the effects of testosterone?
Develops and controls male sexual characteristics, controls production of sperm
What are the effects of insulin?
Lowers blood glucose level
What are the effects of glucagon?
Raises blood glucose level
What are the effects of the antidiuretic hormone?
Reduces the amount of water reabsorbed from kidneys
What are the effects of progesterone?
Thickens wall of uterus, helps bones absorb calcium.
How does the endocrine system use hormones to carry chemical messages around the body?
- Hormones are synthesised with a specific three-dimensional shape, then are secreted into the bloodstream.
- They travel through the bloodstream, and bind onto receptors that match the hormone’s shape. They will not bind to any other receptors.
- Hormones can only affect cells that display receptors that are specific to them.
How does the endocrine system use the mechanism of negative feedback>
- Negative feedback loops are used to maintain homeostasis.
- If a stimulus is received indicating that a hormone-controlled effect is happening too much, the response is to produce less of the hormone to reduce the effects.
- Vice versa- if there is too little of a condition, we ‘increase’ the condition.
- Negative feedback loops can increase or decrease a stimulus, inhibiting the ability of the stimulus to continue as it did prior to sensing of the receptor.
What are two common problems with the endocrine system?
Diabetes: occurs when there is a hormone imbalance.
Goitre: occurs when the thyroid gland becomes enlarged.
List the eight glands of the endocrine system.
- Hypothalamus
- Pineal gland
- Pituitary gland
- Thyroid
- Parathyroid
- Adrenal
- Pancreas
- Gonads
Where is the hypothalamus located?
Base of brain
Where is the pineal gland located?
In the brain
Where is the pituitary gland located?
The inferior part of the brain
Where is the thyroid located?
The neck
Where is the parathyroid located?
The neck
Where is the adrenal gland located?
The top of each kidney
Where is the pancreas located?
Back of abdomen, behind stomach
Where are the gonads located?
Ovaries (female), testis (male)
What is the role of the hypothalamus?
Releases hormones that control release of other hormones from pituitary gland (growth hormones etc.)
What is the role of the pineal gland?
Produces melatonin, which affects daily biological rhythms (sleep patterns, reproductive hormones etc.)
What is the role of the pituitary gland?
Sends signals to other endocrine glands to stimulate/inhibit own hormone production
Anterior: releases growth hormone, prolactin, thyroid-stimulating hormone etc.
Posterior: releases oxytocin, antidiuretic etc.
What is the role of the thyroid?
Regulates body metabolism, growth and development and nervous system
What is the role of the parathyroid?
Responsible for calcium regulation / increasing blood calcium levels / decreasing blood phosphate levels
What is the role of the adrenal gland?
Regulates essential bodily functions and increases body metabolism in ‘fight or flight’ stress response
What is the role of the pancreas?
Helps maintain blood sugar levels. Makes insulin and glucagon (makes enzymes / raises level of glucose)
What is the role of the ovaries?
secretes estrogen and progesterone
What is the role of the testis?
produces sperm (spermatogenesis) and androgens (testosterone).
List the five senses of the body.
- Sight
- Hearing
- Smell
- Taste
- Touch
What type of stimulus does sight detect?
Light
What type of stimulus does hearing detect?
Sound/gravity
What type of stimulus does smell detect?
Chemicals
What type of stimulus does taste detect?
Chemicals
What type of stimulus does touch detect?
Pressure / touch / heat
What type of sensory neuron is involved with sight?
Photoreceptors
What type of sensory neuron is involved with hearing?
Mechanoreceptors
Hair cells
Semicircular canals
What type of sensory neuron is involved with smell?
Chemoreceptors
What type of sensory neuron is involved with taste?
Chemoreceptors
What type of sensory neuron is involved with touch?
Mechanoreceptors
Thermoreceptors
In a flame test, what colour does sodium carbonate emit?
Orange
In a flame test, what colour does copper carbonate emit?
Orange + Yellow + Green
In a flame test, what colour does potassium carbonate emit?
Orange-pink
In a flame test, what colour does barium sulfate emit?
Orange
In a flame test, what colour does calcium carbonate emit?
Red
In a flame test, what colour does strontium carbonate emit?
Bright red/orange/pink
List the six samples tested in flame tests.
- Sodium carbonate
- Copper carbonate
- Potassium carbonate
- Barium sulfate
- Calcium carbonate
- Strontium Carbonate
