C1

Question 1

Define an Isotope

Answer 1

Atoms of the same element with the same number of protons but different number of neutrons

Question 2

RAM equation

Answer 2

Sum of (Isotope abundance x Isotope mass) /
Sum of abundance of all isotopes

Question 3

Define molecule
Define compound
Define mixture

Answer 3

Group of two or atoms held together by chemical bonds
Substances that contain two or more different elements chemically bonded
Two or more substances that are not chemically bonded

Question 4

Define a solvent

Answer 4

A solvent is a liquid in which substances can dissolve.

Question 5

Describe the process of crystallisation
(4 marks)

Answer 5

Pour the solution into an evaporating dish and heat gently using a Bunsen burner.

Stop heating it when crystals start to form and allow it to cool down.

Then either leave it to allow the rest of the water to evaporate, or filter out the crystals using filter paper and a funnel.

dry the crystals in a warm oven.

Question 6

Describe the process of evaporation for crystals (4 marks)

Answer 6

Pour the solution into an evaporating dish
Slowly heat solution
Solvent will evaporate and the solution will get more concentrated
Crystals will form
Kepp heating the evaporating dish until there are only dry crystals left

Question 7

Describe Chromatography (6 marks)

Answer 7

Draw line near the bottom of a sheet of filter paper
Add a spot of the ink to the line and place the sheet in a beaker of water
Make sure ink isn’t touching the solvent (so doesn’t dissolve into it)
Place lid on top of container to stop the solvent evaporating
Each different dye in the ink will move up the paper at a different rate so the dyes will separate out
When the solvent has nearly reached the top of the paper, take the paper out of the beaker and leave it to dry

Question 8

(Why do u use a pencil to draw the line (in chromatography)

Answer 8

Pencil marks are insoluble and wont dissolve in the solvent

Question 9

How was the early periodic table arranged

Answer 9

Elements arranged in order of atomic weIght

Question 10

How did Mendeleev arrange the periodic table and what can you say about properties of elements in the same group

Answer 10

Elements arranged by atomic number
Elements in the same group have similar properties

Question 11

Why did Mendeleev leave gaps in the table

Answer 11

For undiscovered elements and to ensure it fit the pattern

Question 12

Why is filtration done and given an example of everyday use

Answer 12

To separate a solid from a solution - To get sand from a mixture of sand, salt and water

Question 13

Why crystallization is done and give example of everyday use

Answer 13

To separate a solid from a solution - to get pure crystals of salt from salty water

Question 14

Why is simple distillation done and give example of everyday use

Answer 14

To separate a solvent from a solution - to get pure water from salty water

Question 15

Why is fractional distillation and give example of everyday use

Answer 15

Separating a mixture of liquids each with different boiling points - to separate the different compounds in crude oil

Question 16

Why is chromatography done and give example of everyday use

Answer 16

Separating substances in a mixture - to separate out the dyes in food colouring

Question 17

History of the atom in order ( 5 marks)

Answer 17

Dalton - tiny solid spheres that could not be divided
JJ Thomson - A ball of positive charge with negative electrons embedded in it
Rutherford nuclear model - positively charged nucleus at the centre surrounded by negative electrons
Bohr - electrons orbit the nucleus in shells
Chadwick - neutrons are in the nucleus

Question 18

Describe and explain the trend as you go down group 1 ( 5 marks)

Answer 18

Reactivity increases - outer electron is more easily lost - weaker attraction between positive nucleus - weaker intermolecular force - electron further away from positive nucleus lower down the group - lower mp/bp
Higher ram

Question 19

Word equation for metals reacting with oxygen
Word equation for metals reacting with water
Word equation for metals reacting with chlorine
Name 3 substances that group 1 reacts with

Answer 19

Metal + Oxygen – metal oxide
Metal + water – metal hydroxide + hydrogen
Metal + chlorine – metal chlorine
Water, oxygen and chlorine

Question 20

Properties of metals (4 marks)

Answer 20

Conductors
High melting and boiling points
Ductile
Malleable

Question 21

Properties of non metals (2 marks)

Answer 21

Insulators
Low melting and boiling points

Question 22

Describe and explain the trend as you go down group 7

Answer 22

Becomes less reactive - harder to gain an extra electron, because its outer shell is further from the nucleus
Higher melting and boiling point

Question 23

Name two things halogens react with

Answer 23

Metals and hydrogen

Question 24

Word equation for metals reacting with metals (halogens)

Answer 24

Metal + halogen – metal halide

Question 25

Word equation for hydrogen reacting with halogens

Answer 25

Hydrogen + halogen – hydrogen halide

Question 26

Fractional distillation bruh ( 6 marks)

Answer 26

Put mixture in flask and stick a fractionating column on top then heat it
Different liquids will have different bps - will evaporate at different temp
Liquid w lowest bp evaporates first
Liquids with higher bp might also start to evaporate
Column is cooler towards the top - they will only get part of the way up before condensing and running back down towards the flask
when first liquid has been collected , raise the temperature until next one reaches the top