C1: Atoms

Question 1

What is an element?

Answer 1

A substance containing only one type of atom

Question 2

What is a compound?

Answer 2

A substance containing two or more different types of atoms CHEMICALLY BONDED

Question 3

What is the conservation of mass?

Answer 3

Atoms can neither be created or destroyed in a reaction - equations must be BALANCED

Question 4

What is a mixture?

Answer 4

Consists of different substances NOT CHEMICALLY BONDED

Question 5

What does filtration do?

Answer 5

Removes large, insoluble particles from a liquid

Question 6

How does evaporation separate substances?

Answer 6

Leaves behind crystals of a dissolved substance (solute) if heated gently

Question 7

What does distillation involve?

Answer 7

Condensing the evaporated solvent and collecting it

Question 8

What can fractional distillation do?

Answer 8

Separate liquids due to their different boiling points

Question 9

What are characteristics of a solid?

Answer 9

• Arranged in a regular lattice
• Vibrate about fixed positions
• Cannot be compressed

Question 10

What are characteristics of a liquid?

Answer 10

• Particles have no regular arrangement
• Able to move past each other
• Cannot be compressed

Question 11

What are characteristics of a gas?

Answer 11

-Particles are far apart
- Move randomly at fast speeds
-Can be compressed

Question 12

How does heat cause melting/evaporation?

Answer 12

The energy overcomes the electrostatic forces of attraction
Physical change

Question 13

What are the different state symbols?

Answer 13

Solid = s
Liquid = l
Gas = g
Substance in a solution is aqueous = aq

Question 14

How does chromatography work?

Answer 14

Causes substance to rise up paper due to capillary action. Lighter particles move further up

Question 15

What did ancient Greeks believe matter was made up of?

Answer 15

Invisible particles

Question 16

What was JJ Thomson’s atomic model?

Answer 16

-Plum pudding model
-Cloud of positive charge with negative electrons dotted in it

Question 17

What did Ernest Rutherford discover?

Answer 17

-The nucleus was small and positively charged
-Alpha scattering
-Most alpha particles went through gold leaf, very few reflected back

Question 18

What did Neil’s Bohr discover?

Answer 18

Electrons exist in shells

Question 19

What did James Chadwick determine?

Answer 19

The nucleus must contain neutrons as well as protons

Question 20

What is the relative mass and charge of a proton?

Answer 20

Relative mass = 1
Relative charge = +1

Question 21

What is the relative mass and charge of a neutron?

Answer 21

Relative mass = 1
Relative charge = 0

Question 22

What is the relative mass and charge of an electron?

Answer 22

Relative mass = almost 0
Relative charge = -1

Question 23

What is the atomic number?

Answer 23

-The number of protons in a nucleus
-Bottom number
-Also tells us number of electrons if neutral

Question 24

What is an ion?

Answer 24

-A charged atom
-Has a different number of electrons

Question 25

What is the mass number?

Answer 25

-The number of protons + neutrons in a nucleus
-Top number

Question 26

What are isotopes?

Answer 26

Same element, different numbers of neutrons

Question 27

What is the relative abundance of chlorine 35 & 37?

Answer 27

Chlorine-35 = 75%
Chlorine-37 = 25%

Question 28

How do you work out average relative atomic mass?

Answer 28

Average mass = total mass of 100 atoms / 100

Question 29

How were elements initially ordered?

Answer 29

-According to their ATOMIC ‘WEIGHT’
-Some grouped together due to having SIMILAR PROPERTIES

Question 30

What did Dimitri Mendeleev do?

Answer 30

-Left gaps in table for predicted elements

Question 31

How many electrons can be on the first, second and third shells?

Answer 31

First = 2
Second = 8
Third = 8

Question 32

What do metals do to gain an empty outer shell?

Answer 32

Donate electrons to form positive ions

Question 33

What do non-metals do to gain a full outer shell?

Answer 33

Accept electrons to form negative ions
Can also share electrons

Question 34

What do groups tell us?

Answer 34

The number of electrons in the outer shell

Question 35

What are atoms in group 1 called?

Answer 35

The alkali metals

Question 36

What are characteristics of group 1 metals?

Answer 36

-Ions are all (1)+
-React with water to produce an alkali
-Get more reactive down the group

Question 37

Why do metals become more reactive down the group?

Answer 37

-The outer electron is further from the nucleus
-Donated more readily as the force of attraction is less

Question 38

What are atoms in group 7 called?

Answer 38

The halogens

Question 39

What are characteristics of group 7 atoms?

Answer 39

-Ions are all (1)-
-Become less reactive down the group
-Boiling point increases down the group

Question 40

Why do group 7 atoms become less reactive down the group?

Answer 40

-The outer shell is further from the nucleus
-The electrostatic force between the nucleus and the outer shell is weaker

Question 41

Why are noble gases (group 8) very unreactive?

Answer 41

They already have an empty/full outer shell

Question 42

Why can you get different ions of transition metale.g. Iron (II), Iron (III)?

Answer 42

They can donate different numbers of electrons