Topic 1 States + Periodic Table +Electrons

Question 1

Describe a gas

Answer 1

Particles are random and far apart

The particles are fast in all directions

Question 2

Describe a liquid

Answer 2

Particles are random and close together

They move around each other

Question 3

Describe a solid

Answer 3

The particles are regular and close together

They vibrate around a fixed position

Question 4

How does a solid go to a liquid then to a gas?

Answer 4

Melting then the liquid evaporates(boiling)

Question 5

How does a gas go to a liquid then to a solid?

Answer 5

The gas condenses and then the liquid freezes

Question 6

How does a solid go to a gas and vice Versa?

Answer 6

Solid - gas is sublimation

Gas - solid is deposition

Question 7

How are particles attracted to each other?

Answer 7

By weak forces of attraction (attractive forces)

Question 8

What happens when a liquid is Evaporated?

Answer 8

The attractive forces between the particles are overcome because energy is transferred from the surroundings to the particles

Question 9

Why does the temperature stay constant when a solid is changing state to a liquid?

Answer 9

The substance is still being heated but the added energy is making the particles break away from their fixed arrangement

Question 10

Why does the temperature stay constant when a liquid is boiled?

Answer 10

Because the particles are escaping from the liquid to form a gas

Question 11

If the substance is below melting/between melting and boiling/above boiling, what state will it be?

Answer 11

Solid/Liquid/Gas

Question 12

What is a pure substance?

Answer 12

It cannot be changed
The substance is the same in all parts (when a piece of substance is looked at)(the same fixed composition in all parts)
Can’t separate using physical methods

Question 13

What is a mixture?

Answer 13

Contains elements/compounds that are not chemically joined together
Can use physical methods to separate the substance

Question 14

What is a solution?

Answer 14

A mixture of dissolved substances (I.e. solutes) in a liquid called the solvent

Question 15

How do you create crystals?

Answer 15

Mix the solution together
Line a funnel with filter paper. This allows the solvent and solutes to pass through and collect in the beaker. This is the filtrate.
Insoluble substances that can’t get through are the residue
A Bunsen burner is then used to heat the evaporating basin (which is over a beaker filled with boiling water)
You then stop heating when crystals start to form and leave the evaporating basin in a dry place to allow the crystals to form/crystallise.

Question 16

How can you reduce the risks during crystallisation?

Answer 16

Wear goggles

Not to overheat the basin as hot crystals may spit out or change crystals chemically

Question 17

What is chromatography?

Answer 17

A technique used to find out which coloured compounds a mixture contains

Question 18

Why is paper chromatography a simpler technique?

Answer 18

Some compounds dissolve better in the solvent (water) than others

Question 19

What is the mobile phase and what does it do?

Answer 19

The solvent - when it moves along the paper, it carries the different substances in the mixture at different speeds, separating them.

Question 20

What is the stationary phase?

Answer 20

The paper (contains it)

Question 21

What is the chromatogram?

Answer 21

The paper with all separate components

Question 22

How do you calculate the rF value?

Answer 22

Distance moved by spot / distance moved by solvent

Question 23

What is paper chromatography used for?

Answer 23

Distinguishing between pure and impure substances

Identifying substances by calculate Rf values

Question 24

Why do you use pencil?

Answer 24

Because it won’t be carried up by the solvent

Question 25

What is distillation?

Answer 25

Separating a liquid from a mixture by evaporating the liquid and then condensing it.

Question 26

Why is the liquid pure?

Answer 26

When the liquid is heated, only the water evaporates and turns to gas as the solids have a higher boiling point and are left behind.
The gas( water vapour) is then condensed and collected elsewhere and because it is purely water, the liquid is pure.

Question 27

What is fractional distillation?

Answer 27

Separating two or more liquids by first evaporating the liquid with the lower boiling point and collecting it as vapour first

Question 28

How does it work?

Answer 28

The mixture will be separated into different fractions. The first fraction to be evaporated will be the one with the lowest boiling point.

Question 29

How are the different fractions collected? (Use equipment)

Answer 29

A column is fixed above the distillation flask.
When the flask is heated, the hot vapour rises up the column
The water vapour will then condense when it hits the top of column (at first it won’t be collected)
Therefore, it is hottest at bottom of column but coolest as you for further up
The fraction with the lowest boiling point will reach the top of the column first and the vapour will then pass into the condenser and this will carry on with the different fractions when the temperature rises.

Question 30

Why is fractional distillation useful?

Answer 30

It separates the different fractions in crude oil
Makes alcoholic drinks e,g, whiskey
To separate gasses in the air (once they’ve cooled down and been condensed into a liquid)

Question 31

How can you set up a chromatography experiment and a distillation experiment for ink?

Answer 31

Distillation -x-
Ink should be in a flask which is being heated by Bunsen burner.
The gas will rise to top and travel through a delivery tube and into a boiling tube in ice cold water. This will condense the gas back into a liquid.
Chrome -+-
Draw a pencil line about 2cm from bottom of paper
Add a small spot of ink to line and add water to a container of 1cm depth
Place the paper into the container/water but make sure the paper is up straight
Take the paper out before it reaches top and mark the end of the solvent using a pencil and leave to dry
Measure the distance the solvent/spot have moved to calculate the Rf value

Question 32

How to purify sea water (simply)?

Answer 32

Heat the water and collect the water vapour

Then cool the vapour so it condenses back into a liquid which will be pure/ water without containing the dissolved salts

Question 33

What is chemical analysis?

Answer 33

Using chemical reactions or sensitive machines to identify and measure the substances in a sample

Question 34

How is water made so it is suitable for drinking?

Answer 34

Water from a water source is first put into a sedimentation tank which allows small particles to settle out
It then goes into the filtration tower contains sand and gravel. The water is filtered through the sand and gravel so any insoluble substances are left behind
Chlorine is then added to kill bacteria or other microorganisms in the water before being stored in a water tower

Question 35

What can fresh water contain?

Answer 35

Leaves and twigs
Insoluble particles e.g. grit
Soluble substances like salts and fertilisers
Bacteria and other micro organisms

Question 36

What was Dalton’s atomic theory?

Answer 36

He thought all matter was made up of small particles called atoms
Atoms are tiny and cannot be created or destroyed
The atoms in an element are identical

Question 37

What is the charge and mass of a proton?

Answer 37

Charge is +1 and mass is 1

Question 38

What is the charge and mass of electron?

Answer 38

Charge is -1 and mass is 1/1835 or 1/1840 or negligible

Question 39

What is the charge and mass of neutron?

Answer 39

0 charge (neutral) and 1 mass

Question 40

What was the gold foil experiment?

Answer 40

He fired tiny positive particles at a thin piece of gold foil
Surprisingly, most of the particles passed straight through
However, some deflected it and some bounced back

Question 41

What is an isotope?

Answer 41

And element with the same atomic number but different mass number

Question 42

How do you calculate the rfm of isotopes?

Answer 42

(% x rfm) + (% x rfm) all divided by 100(no. Of atoms)

Question 43

How did Mendeleev organise the periodic table?

Answer 43

He arranged elements in increasing relative atomic masses but left gaps
Also tried to group elements if they had similar chemical properties

Question 44

What did Henry Moseley discover?

Answer 44

The atomic number is the same as the number of protons in a nucleus

Question 45

How is the periodic table arranged now?

Answer 45

Arranged in order of increasing atomic number (not rfm)
Elements in a row or period are increasing in atomic number
Elements with similar properties are in the same column or group
Non-metals on right of table

Question 46

How many electrons can the first two shells hold?

Answer 46

1st shell 2

2nd shell 8

Question 47

How is the periodic table related to the electronic configuration?

Answer 47

Number row = number of electron shells

Group number = number of outer electrons in outer shell (group 0 have full shell)