Science COPY Flashcards
What is an Isotope
- It is where the atoms of an element have the same number of protons but different neutrons.
- Isotopes have same atomic number different mass
eg carbon has three isotopes: carbon-12, carbon-13, and carbon-14. Carbon-12 has 6 neutrons, carbon-13 has 7 neutrons, and carbon-14 has 8 neutrons, but all three isotopes have 6 protons in their nuclei, making them all carbon atoms.
What is a molecule
A collection of 2 or more atoms
What is a Neutron
Uncharged subatomic particle of an atom
What observations when burn magnesium
Gives off heat
Burns bright
White powder
Fast Reaction
What is a valence electron
They are the electrons in the outermost shell of an atom, determining its chemical properties and bonding behavior.
What is metalic bonding
- Metallic bonding occurs when a group of metal atoms share valence electrons.
- The electrons that can move freely between the metal ions.
- These shared electron makes metals good conductors of electricity and heat
What makes metal malleable
- Because electrons free to move
- When a force is applied, the free electrons help the metal atoms slide past each other without breaking the bonds.
- This allows the metal to change shape without fracturing,
What is an Ion
- Ions are charged particles.
- It is an atom that has lost or gained an electron
Where are protons found?
In the nucleus - they cannot be gained or lost
What is a covalent bond
- A covalent bond is a type of chemical bond that forms when two non metal atoms share pairs of electron
- Sharing of electrons creates a strong bond that holds the atoms together to form molecules.
- They remain neutral
What are cations
- Cations are positively charged ions formed when an atom loses one or more electrons.
- This loss of electrons results in the atom having more protons than electrons, giving it a net positive charge.
- Cations are typically formed by metals, which tend to lose electrons to achieve a stable electron configuration,
What are anions
- Negative Ions
Examples include chloride ions (Cl⁻), oxide ions (O²⁻), and nitride ions (N³⁻).
Where are metals and non-metals placed on the periodic table
- Metals on left
- Non metals on right
Why are metals good conductors of electricity?
Because they have free-moving electrons that can carry electric charge easily.
What 2 metals have most violent reaction?
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Potassium and Sodium
What 3 metals do not react?
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Copper Silver Gold
In an atom what is uncharged?
Neutron
How is the periodic table ordered?
In order of atomic number and those with similar properties /reactivity properties
If the electron arrangement is 2,8 what is the symbol. And what is the characteristic of this element/
Ne
Full outer shell of electrons
If you react magnesium with hydrochloric acid what gas will be collected
Hydrogen
If you lit hydrogen - what would you expect to happen?
Pop and red flash of light
How do you calculate the number of neutrons?
- You subtract the number of protons (which is the atomic number) from the mass number.
- The mass number represents the total number of protons and neutrons in the nucleus of an atom.
Describe what makes something a living thing
MRS GREN:
- Movement
- Reproduction
- Sensitivity
- Growth
- Respiration
- Excretion
- Nutrition
What is a Species?
A group of organisms that can reproduce and produce fertile offspring
What is a population?
It is a member of the same species living in the same geographical area
What is a community?
Interaction of populations of living things found in a habitat
What is an ecosystem?
- An ecosystem is all the living and non-living factors of an area and how they interact with each other.
- They can be natural, such as the ocean.
- Or man-made: eg a vegetable garden is an ecosystem!
What is a biotic factor
All living organisms in an ecosystem
eg tree, mouse
What is an abiotic factor
All non living organisms in an ecosystem
eg rain, temperature
What is ecology?
It is the study of living things, their interactions and their environment.
What are ecologists?
People who study ecology
Where does all energy in the ecosystem come from?
The sun
Describe how plants capture light energy
Using photosynthesis they convert CO2, water sunlight into glucose
What is a food chain?
- Shows how energy is transferred from one organism to another.
- Starting with plants
In food chain what is a producer, primary consumer, secondary consumer and tertiary consumer
- A producer is an organism that produces its own food through photosynthesis eg plant
- A primary consumer eats producers
- A secondary consumer eats primary consumers
- A tertiary consumer eats secondary consumers.
What is a trophic level in food chain?
The levels of the food chain
What is symbiosis?
- The relationship between two species.
- In symbiotic relationships, at least one of the species involved benefits from the relationship.
Mutualism
Is where both species benefit
Commensalism
Where one species benetifts and the other not harmed - eg barnicle on whale
Paratism
Where one harmed and the other benefits
How have humans impacted habitat destruction
- Clearing land for agriculture
- Housing development
- Pollution and mining,
- These destroys the ecosystem of many plants and animals which alters the food web by changing species present
What is Pollution?
- Pollution is when harmful substances get into the environment (air, water, or soil)
- It causes damage to living things and ecosystems.
Describe Biodegradable and Non Biodegradable pollutants
- Biodegradable pollutants are substances that can be broken down by living organisms into harmless substances over time - like food waste.
- Non-biodegradable pollutants are substances that do not break down and stay for a long time, causing harm eg plastic.
What is Eutrophication
- Eutrophication is when too many nutrients, like nitrogen and phosphorus, enter water, usually from fertilizers or sewage.
- This causes excessive growth of algae and plants, which cuts oxygen levels in the water, leading to death of aquatic life.
What is biodiversity
Biodiversity refers to the variety and number of living organisms populations in ecosystem including plants, animals, fungi, and microorganisms
What is conservation
- It is the looking after the worlds biodiversity
- This reducing the number of species becoming extinct
What is biodiversity affected by
Climate Change
Habitat destruction
Over harvesting
Pollution
Why is carbon dioxide in the atmosphere increasing?
Burning fossil fuels
Large scale forestry
What is the effect of increasing carbon dioxide?
Global Warming
Respiratory disease
What happens when a primary consumer (rabbit) is eliminated from an ecosystem?
- When a primary consumer is eliminated it disrupts the food chain
- Eg if rabbits (primary consumers) die, grass will increase because there are no rabbits eating it.
- The animals that eat rabbits will have less food, which could see thier population decrease.
- It has a chain reaction that can affect many different animals
What is an element
A substance with only one type of atom
How do the phyiscal properties of elements differ?
Boiling point, heat, electrical conductivity, solid, liquid, gas
How is Periodic Table organised
Smallest to biggest
What is atomic number
The smallest number in atom box and = the number of protons
How do you calculate neutrons
Take away Protons (the atomic number) with the mass
What does Mass number represent?
Protons and neutrons in that element
What does diatomic mean and what are the 7 elements
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- Diatomic simply means that a molecule is made up of two atoms of the same element bonded together
- They never want to be alone
- Hydrogen (H2)
- Nitrogen (N2)
- Fluorine (F2)
- Oxygen (O2)
- Iodine (I2)
- Chlorine (Cl2)
- Bromine (Br2)
What a the qualities of a metal?
Shiny
High melting points
Good conductors of electricity
Good conductors of heat
High density
Malleable
Why would you repeat an experiment three times?
To have more reliable results
What is an independent variable?
Is something in an experiment that changes on purpose in an experiment to see what effect it has on dependent variable
What is a dependent variable?
- It is what is being measured or observed in an experiment;
- it changes dependent on the independent variable.
What is a controlled variable?
- The variable that kept constant or unchanged
- To ensure that any effects are due to the independent variable and not other factors.
What is pressure?
Force per unit area
What are Pressure, Force and Area measured in?
- P Pressure - Pa Pascal
- F Force - N Newton
- A Area - m² Metres squared
How do you calculate density?
Density= Volume/Mass
What is the unit of density?
grams per cubic centimeter (g/cm³).
What does density mean?
- How closely packed particles are in a solid, liquid and a gas.
What is symbol for Potassium
K
What is symbol for Sodium
Na
What is symbol for Copper
Cu
What is symbol for Iron
Fe
What is symbol for Silver
Ag
What is symbol for Mercury
Hg
What is chemical formula for Sodium Chloride
NaCl
What is chemical formula for Hydrogen Peroxide
H2O2
Hydrogen peroxide is a compound consisting of two hydrogen atoms bonded to two oxygen atoms.
On a line graph where does the independent variable go?
Horizontal - X axis
Always start numbeing axis from?
Zero
What does the line graph need to have on it?
Title, best fit line, label axis, axes even steps, circle error points, graph should cover half of page
In a line graph what order should the title be?
Vertical then Horizontal
Where should change variable go on the graph?
Horizontal line
What do primary consumers eat?
Plants - Herbivores
What do secondary consumers eat
Animals - Carnivores
What is velocity?
Velocity is the rate of change of distance with time it is measured as metres per second.
What is weight, how do you calculate
F= M x G
Unit is N (newton)
The weight of an object is defined as the force of gravity on the object and may be calculated as the mass times the acceleration of gravity.
How to calculate Pressure
Pressure = Force/Area
Unit is Pascal
In Physics, pressure is a measure of how much force is acting on a certain area.
Solids, liquids and gases can all exert pressure
Why does weight change depending on where you are?
The weight of an object is not the same everywhere because the size of the force of gravity is not the same everywhere – the force of gravity is less on the moon than on the Earth, so, the weight of the object is less on the moon than on the Earth.
What is Mass?
Mass is a measure of the amount of matter in an object.
Is Mass the same everywhere in the universe?
YES.
Mass is the same everywhere in the universe.
Can you change density of a gas?
Yes
This is because the particles can be different distances apart. This means you can change the volume without changing the mass.
Can you change the density of a solid or a liquid?
No
You cannot change the density of a liquid or solid.
This is because the mass and volume are linked: to increase the volume you have to increase the mass by the same amount.
What is Force?
A force is a push or a pull.
Eg, when you push open a door you must apply a force to the door. You also must apply a force to pull open a drawer.
Explain why snow shoes work.
Snow shoes have a much large surface area than say a sneaker.
This spreads spread the force over a larger area and reduce the pressure on the snow - this stops people sinking into the snow.
Explain why tractor tyres work
Tractor tyres are wide - this reduces the pressure they exert and are less likely to sink in to wet ground
Define Pressure
Pressure is force per unit area.
Why is a sharp knife easier to cut with
When using a sharp knife, the small area of the blade creates a large pressure, making cutting easier.
What is friction
Friction is a force that always opposes motion.
It acts in the opposite direction to the one in which the box is moving.
What is an example of a non contact force
Non-contact forces are forces that act between two objects that are not physically touching each other.
Example: Magnetic force, gravity
What is a contact force?
Forces that act between two objects which are physically touching each other.
Example: friction
What happens with non balanced forces
When the forces acting on an object do not balance, the resultant force causes the object to accelerate in the direction of the resultant force.
