C3.5 - Covalent bonding

Question 1

What happens when non-metals react together?

Answer 1

When non-metals react together, their atoms share pairs of electrons to form molecules

Question 2

How are most of the molecules in substances that make up living things held together?

Answer 2

Most of the molecules in substances that make up living things are held together by covalent bonds between non-metal atoms

Question 3

What do the atoms of non-metals generally tend to do to achieve stable electron structures?

Answer 3

The atoms of non-metals generally tend to gain electrons to achieve stable electron structures

Question 4

The atoms of non-metals generally tend to gain electrons to achieve stable electron structures.
When they react together, neither atom can give away electrons.
So they get the electronic structure of a noble gas by sharing electrons.
How are the atoms in the molecules then held together?

Answer 4

The atoms in the molecules are then held together by the shared pairs of electrons

Question 5

Covalent bond

Answer 5

A covalent bond is the bond between 2 atoms that share:
1. 1
Or,
2. More
pairs of electrons

Question 6

1 covalent bond

Answer 6

1 covalent bond is:

1. 1 shared pair of electrons
2. 2 electrons in total in the middle

Question 7

2 covalent bonds

Answer 7

2 covalent bonds are:

1. 2 shared pairs of electrons
2. 4 electrons in total in the middle

Question 8

3 covalent bonds

Answer 8

3 covalent bonds are:

1. 3 shared pairs of electrons
2. 6 electrons in total in the middle

Question 9

Sometimes in covalent bonding what does each atom have?

Answer 9

Sometimes in covalent bonding each atom has the same number of electrons to share

Question 10

What do many substances containing covalent bonds consist of?

Answer 10

Many substances containing covalent bonds consist of small molecules

Question 11

Many substances containing covalent bonds consist of small molecules, for example H2O.
However, what are some covalently bonded substances?

Answer 11

Some covalently bonded substances:

1. Are very different
2. Have giant structures

Question 12

Many substances containing covalent bonds consist of small molecules, for example H2O.
Some covalently bonded substances are very different.
They have giant structures where huge numbers of atoms are held together by a network of covalent bonds.
What are these giant covalent structures sometimes referred to as?

Answer 12

These giant covalent structures are sometimes referred to as macromolecules

Question 13

What does diamond have?

Answer 13

Diamond has a giant covalent structure

Question 14

Diamond has a giant covalent structure.

In diamond, what does each carbon atom do?

Answer 14

In diamond, each carbon atom forms 4 covalent bonds with its neighbours

Question 15

Diamond has a giant covalent structure.
In diamond, each carbon atom forms 4 covalent bonds with its neighbours.
What does this result in?

Answer 15

This results in a rigid giant covalent lattice

Question 16

What do diamonds owe their hardness to?

Answer 16

Diamonds owe their hardness to the way the carbon atoms are arranged in a giant covalent structure

Question 17

Examples of compounds which are bonded covalently

Answer 17

Examples of compounds which are bonded covalently are:

1. Hydrogen chloride gas
2. Carbon monoxide
3. Water

Question 18

When non-metals react together, their atoms share pairs of electrons to form molecules.
This is what?

Answer 18

This is covalent bonding

Question 19

The atoms of non-metals generally tend to gain electrons to achieve stable electron structures.
When they react together, neither atom can give away electrons.
So they get the electronic structure of a noble gas by sharing electrons.
The atoms in the molecules are then held together by the shared pairs of electrons.
These strong bonds between the atoms are called what?

Answer 19

These strong bonds between the atoms are called covalent bonds

Question 20

Sometimes in covalent bonding each atom has the same number of electrons to share, but this is what?

Answer 20

Sometimes in covalent bonding each atom has the same number of electrons to share, but this is not always the case

Question 21

Many substances containing covalent bonds consist of small molecules.
Example

Answer 21

For example, H2O

Question 22

Many substances containing covalent bonds consist of small molecules, for example H2O.
Some covalently bonded substances are very different and have giant structures, where what?

Answer 22

Some covalently bonded substances:

1. Are very different
2. Have giant structures, where huge numbers of atoms are held together by a network of covalent bonds