Lecture 1

Question 1

Why do elements in the same group have similar reaction?

Answer 1

All the elements in a group have similar reactions, because they have the same
number of valency electrons

Question 2

What are Group 1 called?

Answer 2

The alkali metals

Question 3

What are Group 2 called?

Answer 3

The alkaline earth metals

Question 4

What are Group 7 called?

Answer 4

The halogens

Question 5

What are Group 0 called?

Answer 5

The noble gases

Question 6

4 examples of alkali metals

Answer 6

Lithium, sodium, potassium and cesium

Question 7

Physical properties of alkali metals

Answer 7

They are softer than most metals (can be cut with a knife).
They are good conductors of heat and electricity.
They have low density.
They have low melting and boiling points.

Question 8

How does sodium and lithium react with water?

Answer 8

They react violently with water, giving hydrogen and a hydroxide.

Question 9

What happens in the experiment with potassium and water?

Answer 9

It reacts vigorously with water. Burns violently with a purple flame and disappears extremely quickly.

Question 10

Chemical reaction between alkali metals and chlorine

Answer 10

They burst into flame and burn brightly forming chlorides.

Question 11

Chemical Reaction between alkali metals and oxygen

Answer 11

They burn fiercely to form oxides

Question 12

What are alkali metals stored under

Answer 12

Stored under oil to prevent reaction with oxygen and water.

Question 13

Why are alkali metals so reactive?

Answer 13

Because they need to lose only one electron, to gain a stable outer shell. So they have a strong drive to react with other elements and compounds.

Question 14

Why does reactivity increase down group 1

Answer 14

This is because the outer electron is getting further away from the nucleus. This means the attraction is lower. This outer electron is easier to lose.

Question 15

What’s the reason for lithium holding onto its outer electron more strongly than sodium?

Answer 15

Because it has a lower atomic radius than sodium so nuclear attractive force acts on valence shell more on lithium.

Question 16

Name 4 alkaline earth metals

Answer 16

Beryllium, magnesium, calcium and barium

Question 17

Alkaline metals reaction with oxygen

Answer 17

They burn in air and more rapidly in oxygen. They get more reactive with oxygen going down the group.

Question 18

Uses of alkaline metals?

Answer 18

Limestone (calcium carbonate)= building material/ cement
Slaked line (calcium hydroxide)= used by the farmers to raise the pH of acidic soil.
Barium= used to track the movement of meals on xrays in the field of gastroenterology.

Question 19

Give a reason to explain why atomic radii decrease from Li to F.

Answer 19

Charge increases as the atomic number increases. Force of attraction between valency electrons and nucleus increases.

Question 20

What’s the most metallic and non-metallic elements

Answer 20

Francium is the most metallic as it can lose electrons quickly due to its larger atomic size. In contrast, F is most non-metallic as it can gain electrons rapidly due to its smallest atomic size.