Atomic structure and the periodic table

Question 1

Define atom

Answer 1

The smallest part of an element that can still be recognised as that element

Question 2

Define element

Answer 2

A substance made of only one type of atom

Question 3

Define compound

Answer 3

A substance made of two or more different atoms chemically bonded together

Question 4

Define molecule

Answer 4

A substance made of more than one atom chemically bonded together (can be atoms of the same type!)

Question 5

Define mixture

Answer 5

A substance made of more than one thing not chemically bonded together

Question 6

State the three subatomic particles

Answer 6

Protons, neutrons, electrons

Question 7

State the masses of the subatomic particles

Answer 7

Protons: 1, neutrons: 1, electrons: 0

Question 8

State the relative charges of the subatomic particles

Answer 8

Protons: +1, neutrons: 0, electrons: -1

Question 9

How are the subatomic particles arranged in an atom? (3 marks)

Answer 9

Protons and neutrons in the nucleus, electrons orbiting in shells

Question 10

What is the plum pudding model of the atom?

Answer 10

A ball of positive charge with negative electrons studded into it

Question 11

What did the gold foil experiment prove?

Answer 11

That atoms have dense nucleuses with a positive charge

Question 12

What is the atomic number of an atom?

Answer 12

The number of protons in an atom

Question 13

What is the mass number of an atom?

Answer 13

The number of protons + the number of neutrons in an atom

Question 14

How do you calculate the number of neutrons in an atom?

Answer 14

Mass number - atomic number

Question 15

How are the electrons arranged in atoms?

Answer 15

Orbiting the nucleus in shells

Question 16

How many electrons can go in the first shell?

Answer 16

2

Question 17

How many electrons can go in the second and third shells?

Answer 17

8

Question 18

What are groups in the periodic table?

Answer 18

The columns, numbered 1, 2, 3, 4, 5, 6, 7, 0

Question 19

What can the group tell you about the electrons in an atom?

Answer 19

How many electrons in the outer shell. E.g. carbon is in group 4 so has 4 electrons in the outer shell

Question 20

What are periods in the periodic table?

Answer 20

The rows in the periodic table

Question 21

What can the period tell you about the electrons in an atom?

Answer 21

How many shells an atom has. E.g. carbon is in the second period so has two shells

Question 22

Why did Mendeleev put some elements in groups?

Answer 22

Because they had similar chemical properties (e.g. they reacted violently with water)

Question 23

Why did Mendeleev leave gaps in his periodic table?

Answer 23

For elements that had not been discovered yet

Question 24

What is an ion?

Answer 24

an atom which has lost or gained an electron

Question 25

How many electrons does calcium have?

Answer 25

20 (same as atomic number!)

Question 26

How many electrons does silicon have?

Answer 26

14 (same as atomic number!)

Question 27

How are the electrons in sulphur arranged?

Answer 27

2.8.6 (18 electrons total)

Question 28

How are the electrons in magnesium arranged?

Answer 28

2.8.2 (12 electrons total)

Question 29

How many electrons are in the outer shell of boron?

Answer 29

3 (it is in group 3!)

Question 30

How many electrons are in the outer shell of phosphorous?

Answer 30

5 (it is in group 5!)

Question 31

How many electrons are in the outer shell of sodium?

Answer 31

1 (it is in group 1!)

Question 32

An element has three shells and three electrons in the outer shell. What element is it?

Answer 32

Aluminium (group 3, period 3

Question 33

How many electrons are in the outer shell of Gallium?

Answer 33

3 (it is in group 3!)

Question 34

In terms of electrons, what do group 1 elements have in common?

Answer 34

1 electron in the outer shell

Question 35

In terms of electrons, what do group 7 elements have in common?

Answer 35

7 electrons in the outer shell

Question 36

In terms of electrons, what do group 0 elements have in common?

Answer 36

Full outer shell

Question 37

What is more reactive, lithium or sodium?

Answer 37

Sodium

Question 38

What is more reactive, chlorine or bromine?

Answer 38

Chlorine

Question 39

Define inert

Answer 39

Unreactive

Question 40

Explain why the noble gases are inert

Answer 40

They have full outer shells, so do not need to gain or lose electrons

Question 41

What is a trend?

Answer 41

A pattern in properties

Question 42

State the trend in the melting points of the alkali metals

Answer 42

Gets lower down the group

Question 43

What state is fluorine at room temperature?

Answer 43

Gas

Question 44

What state is chlorine at room temperature?

Answer 44

Gas

Question 45

What state is bromine at room temperature?

Answer 45

liquid

Question 46

What state is iodine at room temperature?

Answer 46

solid

Question 47

Balance the equation: Li + H₂O → LiOH + H₂

Answer 47

2Li + 2H₂ → 2LiOH + H₂

Question 48

Balance the equation: K + H₂O → KOH + H₂

Answer 48

2K + H₂ → KOH + H₂

Question 49

Name LiOH

Answer 49

Lithium hydroxide

Question 50

Name KOH

Answer 50

Potassium hydroxide

Question 51

Explain why the group 1 elements are called alkali metals

Answer 51

They are metals that form alkalis when they react with water

Question 52

What is a displacement reaction?

Answer 52

A reaction in which a more reactive element takes the place of a less reactive element in a compound

Question 53

Explain why the following reaction does not proceed: KBr + I₂

Answer 53

Iodine is less reactive than bromine so cannot displace it

Question 54

Balance the below equation and explain why it is a displacement reaction: KBr + Cl₂ → KCl + Br₂

Answer 54

2KBr + Cl₂ → 2KCl + Br₂ , chlorine has displaced bromine as it is more reactive

Question 55

Explain why fluorine is more reactive than chlorine

Answer 55

Fewer shells/electrons, less shielding (or stronger attraction from nucleus), easier to gain electrons

Question 56

Explain why potassium is more reactive than lithium (3 marks)

Answer 56

More shells/electrons, less shielding (or weaker attraction from nucleus), easier to lose electrons

Question 57

Explain why bromine is less reactive than chlorine (3 marks)

Answer 57

More shells/electrons, more shielding (or weaker attraction from nucleus), harder to gain electrons

Question 58

Explain why sodium is less reactive than caesium (3 marks)

Answer 58

Fewer shells/electrons, less shielding (or stronger attraction from nucleus), harder to lose electrons