Bonding and Calculations

Question 1

What will you find out from the Mass number?

Answer 1

The total number of protons and neutrons.

Question 2

What will you find out from the Atomic number?

Answer 2

The number of protons.

Question 3

Name the three different types of subatomic particles, their charge and where they are found in the atom.

Answer 3

Proton - Positive, found in the nucleus
Neutron - No charge, found in the nucleus
Electron - Negative, found in energy cells outside of the nucleus

Question 4

What is a compound?

Answer 4

Something which is formed when atoms of two or more elements are chemically combined together.

Question 5

What is an isotope?

Answer 5

Different atomic forms of the same element which have the SAME number of PROTONS but a DIFFERENT number of electrons.

Question 6

Name an example of a pair of isotopes.

Answer 6

Carbon 12 and Carbon 14.

Question 7

What happens in ionic bonding?

Answer 7

Atoms lose of gain electrons to form charged particles (ions). These ions tend to ‘latch’ onto oppositely charged ions.

Question 8

Why do atoms take part in ionic bonding?

Answer 8

So that they can gain a full outer shell.

Question 9

Name some examples of atoms that become positively charged ions.

Answer 9

Sodium, Potassium and Calcium are all examples.

Question 10

Name some examples of atoms that become negatively charged ions.

Answer 10

Oxygen ad Chlorine are examples of atoms that gain electrons to become negatively charged overall.

Question 11

What type of structure do ionic compounds have?

Answer 11

They have a regular lattice structure.

Question 12

Name an example of an ionic compound and give its features.

Answer 12

Example: Sodium Chloride
Features:
- closely packed in a regular lattice
- Strong electrostatic forces of attraction between oppositely charged ions in all directions

Question 13

Name the properties of an ionic compound.

Answer 13

Properties:

• High melting points (due to strong attraction between ions)
• High boiling points ( “ )
• When melted are able to carry an electric current
• Dissolve easily in water

Question 14

What are the two pairs of groups that are most likely to form ions?

Answer 14

Groups 1&2 and 6&7.

Question 15

What type of element are likely to give you positive ions?

Answer 15

Metals.

Question 16

What type of element are likely to give you negative ions?

Answer 16

Non-metals.

Question 17

Give a list of Positive ions.

Answer 17

Positive
Group 1     Group 2 
Li+             Be2+
N+             Mg2+
K+             Ca2+

Question 18

Give a list of negative ions.

Answer 18

Group 6 Group 7
O2- F-
Cl-

Question 19

What is the overall charge of an ionic compound?

Answer 19

The overall charge is zero as the positive and negative ions cancel each out.

Question 20

Why is covalent bonding different from ionic bonding?

Answer 20

Ionic bonding is when atoms give electrons however covalent bonding is when atoms share electrons with each other.

Question 21

When do atoms stop making covalent bonds?

Answer 21

When they have a full outer shell.

Question 22

Name 7 examples of atoms that form covalent bonds.

Answer 22

1. Hydrogen - H2
2. Chlorine - Cl2
3. Methane - CH4 (Carbon and Hydrogen)
4. Hydrogen Chloride - HCl (Hydrogen and Chlorine)
5. Ammonia - NH3 (Nitrogen and Hydrogen)
6. Water - H2O (Hydrogen and Oxygen)
7. Oxygen - O2

Question 23

Name the 2 different types of covalent substances.

Answer 23

Simple molecular or Giant structure.

Question 24

Name the features of a simple molecular substance.

Answer 24

Simple molecular substance:

• Very strong covalent bonds
• Very weak forces of attraction between the molecules
• Low melting and boiling points due to the weak intermolecular forces
• They don’t conduct electricity as there are no ions

Question 25

Name the features of a giant covalent structure.

Answer 25

Giant covalent substance:

• Strong covalent bonds
• Very high boiling and melting points
• They don’t conduct electricity as there are no charged ions (graphite however is an exception when molten)

Question 26

Name the features of Diamond.

Answer 26

Diamond features:

• each carbon atom forms 4 covalent bonds in a rigid giant covalent structure
• this structure makes diamond the hardest natural substance which is why it is used for drill tips

Question 27

Name the features of Silicon Dioxide.

Answer 27

Features of Silicon Dioxide:

- structure which contains silicon and oxygen

Question 28

Name the features of Graphite.

Answer 28

Features of Graphite:

• each carbon atom forms 3 covalent bonds
• this creates layers which are able to slide over each other (this is how the layers are able to appear on a page as a pencil marks they ‘have rubbed off’) due to the weak intermolecular forces present
• only non-metal which is a good conductor of heat and electricity as each carbon atom has one delocalised electron