Unit 1 Flashcards
what is matter
Matter is anything that has mass and occupies space.
Ex. Dog
what is a pure substance
A pure substance: all parts of the substance are the same and its properties remain constant.
EX.
~ Aluminium
~ sodium chloride
pure substances are divided into
Elements: Al, N, C, O
Compounds: H20, CO2
what are the two types of mixtures
heterogeneous: all the different parts can be seen
Ex. salsa
homogeneous: all parts look the same
Ex. Milk
when does pop become homogenous
when is goes flat as all carbon dioxide is dissolved. it is now only liquid instead of liquid and gas
what is an atom
The atom is the smallest particle of an element that can exist on its own
what 3 parts are atoms made up of
protons, neutrons, electrons
where are the protons, neutrons, electrons
The protons and neutrons form the dense nucleus in the center of the atom, while the electrons travel around the nucleus of the atom in paths called orbits.
what happens if an atom loses or gain an electron it becomes what
ion
what happens when ions lose electrons
they become a cation
what happens when ions gain electrons
they become a anion
how to calculate neutrons
mass # - atomic # = neutrons
what are isotopes
Isotopes are atoms of an element that have the same number of protons but different numbers of neutrons, and therefore have a different mass number.
give an example of an isotope
The element carbon has 3 isotopes: carbon-12, carbon-13 and carbon-14. All carbon atoms have 6 protons, therefore carbon-12 has 6 neutrons, carbon-13 has 7 neutrons and carbon-14 has 8 neutrons.
what is a radioisotope
-atom with unstable nucleous
-the atom undergoes radioactive decay
- this creates gamma rays
Ex. Hydrogen-3
Where are the electrons found in the atom?
a. in the nucleus
b. evenly spaced in and around the nucleus
c. randomly spaced but usually closer to the nucleus
d. in orbits which are outside the nucleus
d. in orbits which are outside the nucleus
An ion is an atom that has gained or lost which subatomic particle?
a. neutron
b. electron
c. proton
d. scantron
b. electron
how do labels work for WHMIS
- 0-4 on danger
- uses coloured bars to show health, flammability, and physical hazards risks
- use a letter to show what PPE is required
what is found on MSDS (3 things)
- product Information
- hazardous Ingredients
- physical properties
- fire and explosion risks
- reactivity data and health hazards
- preventative measures
- first aid measures
what is a big part of chemistry
the study of changes that occur in substances
what are the two types of changes
physical and chemical
what is physical change
Physical changes are changes that do not produce a new substance
what is an example of physical change
the change in state from solid to liquid when ice melts, or when a piece of copper wire is bent.
what is a chemical change and give 3 sign that a chemical change has taken place
result in the formation of a new substance with new physical and chemical properties
- change in colour
- heat is released (exothermic)
- heat is absorbed (endothermic)
- light is produced
- a precipitate forms
- a gas is produced (bubbles) without heating
- a change in odour
what is the law of conservation of mass
This law states that matter cannot be created, or destroyed, during a chemical reaction. All the atoms present in the reactants must also be present in the products.
how do u uyse the activity series and when
Single Displacement
The lone element most be more reactive than the front element in the compound
what is qualitive analysis
a branch of chemistry that involves identifying elements, ions, and compounds in unknown samples
what is the spectrum of visable light
It is a small portion of the electromagnetic spectrum, which includes ultraviolet, infrared, microwave, and other forms of radiation.
what is an example of the visable light spectrum
Sunlight passing through a haze of raindrops during a rain shower will separate out into a rainbow of colours.
what is the spectrum emitted from visable light look like
a continuous spectrum where each colour blends into each other with no spaces between.
what happens when electrons get excited by heat or electricity
the energy is eventually released in the form of light energy.
what is that light energy called
the element’s emission spectrum, and each element has a unique emission spectrum
is the emission spectrum a continuous rainbow
the emission spectrum of an element is not a continuous rainbow of colours, but distinct bands, referred to as a line spectrum.
how is the emission spectrum helpful
Since each element has a unique emission spectrum, an element’s emission spectrum can be used to identify elements in an unknown sample.
what instrument is used to get the emission spectrum
spectroscope
how does a spectroscope work
the spectroscope separates incoming light into its different components using a prism and the resulting spectrum is reflected onto a scale of wavelengths where the spectrum can be observed.
what is a flame test used for
used to identify certain metal ions
how is a flame test conducted
- the sample being tested is held in the flame
- the colour of the flame determines what metal ion it is
- each metal produces a different coloured flame dpending on their emission spectrum
what colour flame does copper produce
blue green
what colour flame does iron produce
gold
what colour flame does potassium produce
pink
what are the pros of flame tests
they are fast and easy
what are the drawbacks of flame tests
- they can only detect certain elements
- they rely on making a subjective judgement on the colour of the flame, and some elements emit similarly coloured flames
what is a great example if coloured flames being created from different metal ions
fireworks
are flame tests and precipatation tests used anymore
not really as high tech spectrometers are used
what are precipation tests based on
on the fact that cations, (positive ions) form compounds that are either soluble in water or insoluble (do not dissolve), depending on the type of anion (negative ion) present in a solution.
how does the precipatation test work
- they make a guess as to which chemicals may be in the substance
- they test to see if the solution is souble or not
- they add a solute and then watch what happens
- depending on what the solution does will determine what chemical is present
who was Neils Bohr
a scientist who made his main discoveries around 1913 and he was danish
what did the Rutherford Atomic Theory propose
that an atom consists of a central positive nucleus, with electrons moving anywhere around the nucleus.
what could Bohr see from studying the hydrogen atoms atomic semission spectrum
By observing the four spectral lines in hydrogen’s emission spectrum, Bohr could calculate how far away these energy levels would be from the nucleus.
what did Max Planck propose in 1900
that at the atomic level, matter could only absorb or emit discrete quantities of energy, called a quantum of energy
what did Albert Eiesten propose in 1905
that light occurs as quanta of electromagnetic energy that have particle-like properties. He called the particle-like “packets” of energy, photons.
Explain the mouse concept in regardes to atoms energy
If a mouse were climbing the stairs, it could go from stair 1 to stair 2 with a quantum leap, or even from stair 1 to stair 3 if it was a really energetic mouse.
But if the mouse were to climb the railing or banister it could move up at any increment, even 0.1 mm or 1.73 mm further up since the railing is not “quantized” but continuous.
When an atom is “excited” its electrons absorb “packages” (photons) of energy and “jump” to higher energy levels. Then these excited electrons quickly lose the energy and emit this energy as light of a certain colour.
what was the problem with bohrs model
successfully explained the emission spectrum of the hydrogen atom, and ions with only one electron, but it could not explain the emission spectra of atoms with multiple electrons.
What is lab-on-a-chip
Lab-on-a-chip technology could be used to create microscale test clips that healthcare workers in poorly equiped medical clinics can use to diagnose various infectuous and other diseases, without the need for expensive laboratory equipment.
Atom vs ion
Atom is neutral
Ion has a positive or negative charge
What is chemistry
Chemistry is the study of matter and it’s changes
What is a solution
A solution is a homogeneous mixture of two or more substances.
What does WHMIS stand for
Workplace Hazardous MATRIEL Information System
What does MSDS stand for
MATRIEL
Safety
Data
Sheet
What is the standard gas test
You light a splint on fire and put it in a test tube with the below gases and see what it does
- CO2 goes out/lime water test (water goes cloudy)
- H2 pops
- O2 relights (glowing ember)
Give three examples of the flame test
Copper - blue green
Iron - gold
Lithium - red
