Nat 4/5 Structure and Bonding Homework 1

1. What is the reason for atoms of different elements reacting and joining

together ? (1)

2. The atoms in a hydrogen molecule are

held together by a covalent bond.

A covalent bond is a shared pair

of electrons.

(a) Explain how this holds the atoms

together.

(b) What type of atoms are bonded

together in covalent molecules? (2)

2. Draw diagrams to show how the outer electrons form covalent bonds in

each of the following molecules.

(a) oxygen (b) nitrogen hydride (c) hydrogen chloride (3)

3.(a) Make a drawing to show the shape of each of the following molecules

(i) CCl4 (ii) NH3

(b) What is the name given to the shape of molecule in 3(a)(i) (3)

4.a) What is an ion? (1)

b) Explain what holds an ionic bond together (1)

5. The grid below contains six molecules made using a molecular models kit

Identify the molecule that could represent

(a) Hydrogen (b) Water

TOTAL 15 marks

Nat 4/5 Structure and Bonding Homework 2

1. Name the elements present in each of the following compounds.

(a) hydrogen chloride (b) sulphur fluoride

(e) calcium sulphite (f) aluminium carbonate (3)

2. Write the formula for each of the following compounds

(a) Silicon chloride

(b) Sulphur trioxide

3. For the following compounds, state which shape the molecules of this compound will be and draw their structure. (You must work out the formula first).

a. Silicon chloride

b. Phosphorous hydride

c. Hydrogen sulphide

d. Hydrogen fluoride

e. carbon monoxide (5)

2. The following questions refer to the compounds below, where X and Y represent elements.

A. XY B. X2Y C. X2Y3 D. XY2

a. Which letter shows a formula where:

(i) X has a valency of 3 and Y has a valency of 2

(ii) X has a valency of 1 and Y has a valency of 2

(iii) X has a valency of 2 and Y has a valency of 1 (1)

b. Which letter(s) show a compound with a bent shape? (1)

3. An element, X, bonds covalently with chlorine to form a compound with the formula XCl3.

a. Which group does X belong to?

b. Draw a diagram to show the sharing of electrons between X and fluorine. (2)

TOTAL 15 marks

Nat 4/5 Structure and Bonding Homework 3

1. A. sodium fluoride B. potassium nitrate C. ammonium sulphite

a) Which of the above compounds contains only 2 elements?

b) Identify the elements present in each compound. (2)

2. Identify the covalent compounds in the list below:

a. sodium chloride

b. hydrogen chloride

c. nitrogen hydride (ammonia)

c. calcium fluoride

d. sodium hydride (2)

1.(a) Put these substances into a table with the headings Conductor and Insulator

Gold, mercury, oxygen, graphite, sulphur, cobalt

(b) Draw a labelled diagram of the circuit you would use to find out if a

substance is a conductor of electricity. (4)

The table shows the properties of 4 substances A, B, C and D

substance / Melting point / Electrical conductivity
Solid molten solution
A / Low / x x x
B / High / x x x
C / High / x ü ü
D / High / ü ü insol

ü = conductor x = non-conductor insol = insoluble

(a) Using the information in the table, state whether the substances

A,B,C and D are covalent network, covalent molecular, metallic or ionic

(b) Explain your choice each time.

non-conductor when solid. (7)

TOTAL 15 marks

Nat 4/5 Structure and Bonding Homework 4

1. There are two main types of bonds; ionic and covalent.

(a) Explain the difference between the two types

(b) What kind of bonding is likely in a compound containing only non metals?

(b) Name the only non-metal element that conducts electricity. (4)

2.(a) The magnesium ion is written as Mg2+ Give the formula for the ions formed by

(i) calcium (ii) aluminium (iii) chlorine (3)

3. Copy the following table and complete it by adding ‘conducts’ or

‘does not conduct’ in the spaces

Substance / Solid state / Liquid state
Sulphur
Zinc
Calcium oxide

(3)

4. The electrical conductivities of substances A, B and C were measured and

the results are shown

Substance / In solid state / Dissolved in water / In molten state
A / 0 / + / +
B / + / does not dissolve / +
C / 0 / 0 / 0

+ conducts well 0 non-conductor

(a) Which substance could be copper?

(b) Which substance could be lead bromide? (2)

5. (a) If an atom in group 1 loses an electron what charge will the ion have?

(b) If an atom in group 5 gains 3 electrons what charge will the ion have?

TOTAL 15 marks