Atomic Structure and Periodic Table

Question 1

Why is Indium malleable?

Answer 1

• Contains layers that can slide past each other

Question 2

State the name given to a reaction in which heat energy is transferred to the surroundings.

Answer 2

Exothermic

Question 3

Why do all atoms of bromine have the same chemical properties?

Answer 3

Same number of electrons in outer shell

Question 4

What is relative atomic mass ?

Answer 4

The mass of all isotopes of an atom of an element / 1/12th of mass of carbon atom - 12.

Question 5

Suggest, with a reason, which of the atoms Br-79 and Br-81 exists in greater numbers in a sample of Bromine.

Answer 5

Br - 79 as it is closer to the RAM - 79.9

Question 6

Why are atoms neutral?

Answer 6

Atoms are neutral because they have the same number of electrons and protons

Question 7

Why are noble gases not reactive?

Answer 7

• They have a full outer shell
• Noble gases don’t easily lose/gain electrons

Question 8

Why do lithium, sodium, and potassium all have similar chemical properties?

Answer 8

• All in group 1
• They all have the same number of electrons in the outer shell

Question 9

A scientist dissolves a sample of boron trioxide in a beaker of water. A solution forms. Suggest a value for the pH of the solution. Give a reason for your answer.

Answer 9

• The solution would have a pH of (e.g. 4 any value less than 7) because boron oxide is a non-metal oxide and non-metal oxides are acidic

Question 10

Describe the reactivity in group 1

Answer 10

• The reactivity increases as you go down the group
• This is because the elements are increasing in number of shells
• The outer electron is further away from the nucleus
• There is less attraction between the nucleus and the outer electron
• Therefore, it can be easily lost

Question 11

Describe the reactivity in group 7

Answer 11

• Reactivity decreases as you go down
• This is because there are more electronic shells and need to gain one electron by the nucleus which is hard as the electronic shells are further away from the nucleus

Question 12

Describe what you would observe when orange bromine water is added separately to ethane and ethene, in the absence of UV light.

Answer 12

Observation with ethane:
- No change in colour

Observation with ethene:
- Orange to colourless

Question 13

Small pieces of lithium and potassium are added to separate large troughs of water.

State one observation that would be similar for each element, and one that would be different for each element.

Answer 13

Similar: Fizzing

Different: Potassium sparks

Question 14

Explain why potassium sulfide conducts electricity when molten.

Answer 14

Ions are free to move

Question 15

What is meant by the term inert?

Answer 15

Unreactive

Question 16

Why are noble gases inert?

Answer 16

They don’t easily lose/gain electrons

OR

They have a full outer shell

Question 17

What is an atom?

Answer 17

An atom is the smallest piece of an element

Question 18

What is a molecule?

Answer 18

A molecule is formed when atoms join together by chemical bonds

Question 19

Elements are arranged in order of _____ number and so that elements with _____ properties are in columns, known as ______.

Answer 19

atomic, similar, groups

Question 20

Elements in the same periodic group have the same amount of _______ in their _________, which gives them similar chemical properties.

Answer 20

electrons, outer shells

Question 21

elements with the same number of shells of ______ are arranged in rows called ________

Answer 21

electrons, periods

Question 22

the electronic configuration of an element tells you how many ________ are in each ______ around an _______

Answer 22

electrons, shell, electron’s nucleus

Question 23

● If an element is ________ and its oxide is _______ then the element is a metal

Answer 23

conductive, basic

Question 24

● If an element is not _________ and its oxide is _______ then it’s a non-metal

Answer 24

conductive, acidic

Question 25

What is the group number?

Answer 25

gives the number of electrons in the outer shell e.g. group 3 has 3 electrons in the outer shell

Question 26

What is the period number?

Answer 26

gives the number of electron shells e.g. period 1 has 1 shell of
electrons