Unit 1-6

Question 1

What does the period represent?

Answer 1

The number of shells

Question 2

What does the group represent?

Answer 2

The number of valence electrons

Question 3

What is the structure of metalloids?

Answer 3

Giant molecular: Infinite lattice structure

Question 4

What type of bonding is involved in a metalloid?

Answer 4

Covalent: Very strong attraction between atoms due to the attraction between nuclei and shared electrons

Question 5

What are the properties of metalloids?

Answer 5

Very high melting point
Poor conductivity

Question 6

What is the structure of non-metals?

Answer 6

Simple molecular: Discrete molecules

Question 7

What type of bonding is involved in a non-metallic structure?

Answer 7

Molecular (Van-Der-Waals): Weak forces between molecules

Question 8

What are the properties of non-metals?

Answer 8

Low melting point
Nil conductivity

Question 9

Why is the conductivity of metalloids considered to be poor?

Answer 9

Because some structures (graphite) are electrolytes but most aren’t

Question 10

How do oxides of metals react?

Answer 10

Oxides of metals are basic
React with water to form alkali solutions
Will react with acids

Question 11

How do oxides of metalloids react?

Answer 11

Oxides of metalloids are amphoteric
Can act as acidic oxides by reacting with bases
Can act as basic oxides by reacting with acids

Question 12

How do oxides of non-metals react?

Answer 12

Oxides of nonmetals are acidic
React with water to form acidic solutions
Will react with bases

Question 13

Reaction of group 1 elements with water

How does lithium react with water?

Answer 13

Moves slowly on the surface of water
Fizzes as H2 is formed
2Li(s)+2H2O(l)LiOH(aq)+H3(g)

Question 14

Reaction of group 1 elements with water

How does sodium react with water?

Answer 14

Turns into a sphere
Moves quickly on the surface of water
Fizzes as H2 is formed
2Na(s)+2H2O(l)NaOH(aq)+H3(g)

Question 15

Reaction of group 1 elements with water

How does potassium react with water?

Answer 15

Catches fire and burns with a lilac flame
Moves very quickly on the surface of water
Fizzes as H2 is formed
2K(s)+2H2O(l)KOH(aq)+H3(g)

Question 16

Reaction of group 2 elements with water

How does magnesium react with water at room temperature?

Answer 16

Very slow and little reaction
Mg(s)+2H2O(l)Mg(OH)2(aq)+H2(g)

Question 17

Reaction of group 2 elements with water

How does magnesium react with water at when heated in steam?

Answer 17

A white flash produces H2
White powder of MgO forms because the HO thermally decomposes

Question 18

Reaction of group 2 elements with water

How does calcium react with water?

Answer 18

Steadily fizzes as H2 is produced
A cloudy white suspension is formed
The Ca(OH)2 formed is only slightly soluble
Ca(s)+2H2O(l)Ca(OH)2(aq)+H2(g)

Question 19

Reaction of group 1 elements with oxygen

How does lithium react with oxygen?

Answer 19

Red flame burns brighter and more vigorously with oxygen
White powder of lithium oxide is formed
4Li(s)+O2(g)2Li2O(s)

Question 20

Reaction of group 1 elements with oxygen

How does sodium react with oxygen?

Answer 20

Yellow/orange flame burns brighter in oxygen
White powder of sodium oxide is formed
4Na(s)+O2(g)2Na2O(s)

Question 21

Reaction of group 1 elements with oxygen

How does potassium react with oxygen?

Answer 21

Lilac flame burns brighter in oxygen
White powder of potassium oxide is formed
4K(s)+O2(g)2K2O(s)

Question 22

Reaction of group 2 elements with oxygen

How does magnesium react with oxygen?

Answer 22

Bright white flame burns brighter in oxygen
White powder of magnesium oxide is formed
2Mg(s)+O2(g)2MgO(s)

Question 23

Reaction of group 2 elements with oxygen

How does calcium react with oxygen?

Answer 23

Brick red flame burns brighter in oxygen
White powder of calcium oxide is formed
2Ca(s)+O2(g)2CaO(s)

Question 24

What type of agent are metals?

Answer 24

All metals are reducing agents
Need to lose their valence electrons as they react

Question 25

What block do metals belong to?

Answer 25

The S block

Question 26

What is the general formula of group 2 carbonates?

Answer 26

All have the formula XCO3

Question 27

What is the solubility of group 2 carbonates?

Answer 27

Insoluble in water

Question 28

How do group 2 carbonates react with dilute acids?

Answer 28

Metal Carbonate+Acid→Salt+Carbon Dioxide+Water

Question 29

What are the control variables for thermal stability?

Answer 29

1. Same number of moles of carbonate 2. Same concentration and volume of lime water 3. Flame distance 4. Stop heating as soon as the same cloudiness is reached

Question 30

What is thermal decomposition of group 2 carbonates?

Answer 30

Decomposing with heat in order to give oxide and **carbon dioxide** XCO3(s)XO(s)+CO2(g)

Question 31

How is limewater used to investigate thermal decomposition?

Answer 31

Limewater turns milky due to the formation of CaCO3 Speed indicates rate of reaction Slows down the group since elements become more thermally stable

Question 32

What is the general formula of group 2 hydroxides?

Answer 32

All have the formula X(OH)2

Question 33

What happens to the solubility of group 2 hydroxides down the group?

Answer 33

Become more soluble upon descending the group Magnesium is completely insoluble Calcium hydroxide is cloudy since calcium is partially soluble Strontium hydroxide is colourless since strontium is completely soluble

Question 34

How do group 2 hydroxides react with dilute acids?

Answer 34

Base+Acid→Salt+Carbon Dioxide+Water

Question 35

What is the thermal decomposition of group 2 hydroxides?

Answer 35

Decomposing with heat in order to give oxide and steam Ca(OH)2(s)CaO(s)+H2O(g)

Question 36

What happens to thermal stability down the group?

Answer 36

Increases down the group More energy needed to decompose compounds

Question 37

Describe the pH of oxides and hydroxides of group 1

Answer 37

Stronger bases than oxides and hydroxides of group 2 Higher pH values

Question 38

What are the uses of magnesium hydroxide?

Answer 38

Used as a digestion anti-acid medicine Useful due to weakly basic nature Neutralises excess acid

Question 39

What are the uses of calcium hydroxide?

Answer 39

Agriculture to alter soil and lake pH Strong base

Question 40

What are the uses of sodium hydroxide (caustic soda)?

Answer 40

Paper, soaps and ceramics An alkali cleaner to treat aluminium before anodising Neutralising of acids to make salts