States of Matter, Mixtures, Atomic Structure

Question 1

Describe the structure of a gas

Answer 1

Particles are far apart, random, move freely in all directions and you can compress gases

Question 2

Describe the structure of a liquid

Answer 2

Close together, random, particles move around each other, can’t compress

Question 3

Describe the structure of a gas

Answer 3

Particles close together, organised, regular pattern, vibrate on spot and can’t compress

Question 4

Solid to liquid
Liquid to Solid
Liquid to Gas
Gas to Liquid
Gas to Solid
Solid to Gas

Answer 4

Melting
Freezing
Evaporation
Condensation
Deposition
Sublimation

Question 5

Describe Diffusion

Answer 5

The movement of particle from an area of high concentration to low concentration

Question 6

What is a:
Solvent
Solute
Solution
Saturated solution

Answer 6

Liquid which dissolves a solute
Solid which dissolves in a solvent
Solute dissolved in a solvent
The max amount of solute which dissolves in a solvent at a specific temperature

Question 7

State and explain the units of solubility

Answer 7

Solubility is measured by the maximum grams of solute which dissolves in 100g of water
g per 100g of water

Question 8

Describe the separation technique of distillation

Answer 8

A bunsen heats up the liquid
The substance with the lower boiling point evaporates
It travels up the tube and gets cooled into a liquid by an outer sleeve of cold water
It travels down into the beaker
It is used to separate 2 liquids with different boiling points

Question 9

Describe the separation technique of filtration

Answer 9

Filtration is used to separate an insoluble solid from a liquid
Pour the mixture into the filter paper inside a funnel
The insoluble solid should be left as residue in the filter paper
The liquid should be left as the filtrate in the beaker below the funnel

Question 10

Describe the separation technique of crystillation/evaportion

Answer 10

Crystillation/evaporation is used to separate a soluble solute from a solution
Put the substance in a crucible above a Bunsen burner and heat until the solution has evaporated and you are left with the solute

Question 11

Explain chromatography

Answer 11

Paper chromatography is a technique for separating components of a mixture of colours
Place dots of the unknown samples along a pencil drawn line and place the paper in a solvent but make sure the samples are above the line of solvent
Place a lid on top of the beaker to prevent evaporation, or if the solvent is flammable to prevent it catching fire

Question 12

Explain how to calculate the Rf value

Answer 12

Rf = Retention Factor

Rf = Distance moved by sample
——————————————
Distance moved by solvent

The answer is never greater than 1

Question 13

What is the difference between an element and a compound

Answer 13

Element = made of one type of atom
Compound = Made of two or more different types of atoms joined together

Question 14

State the three sub-atomic particles

and their charges and masses

Answer 14

Protons + 1
Neutons / 1
Electrons - 1/1840

Question 15

What is the atomic number

Answer 15

The number of protons in an element

Question 16

What is the mass number

Answer 16

The number of protons and neutrons

Question 17

What is relative atomic mass and how do you calculate it?

Answer 17

The average of all possible numbers of protons = neutrons
(relative abundance x isotopic mass) + ( relative abundance x isotopic mass)
———————————————————————-
Total abundance

Question 18

What is an isotope?

Answer 18

An atom which has lost of gained neutrons but has the same amount of protons and electrons