Bonding

Question 1

What is an ion?

Answer 1

A charged atom or molecule

Question 2

What is ionic bonding?

Answer 2

The electrostatic attraction between oppositely-charged ions

Question 3

Who take part in ionic bonding?

Answer 3

Metals and non-metals

Question 4

What happens to metal atoms when they ionically bond?

Answer 4

They always lose electrons

Question 5

What happens to non-metal atoms when they ionically bond?

Answer 5

They always gain electrons

Question 6

What charge do metals ions become when they bond with non-metals?

Answer 6

Positive

Question 7

What charge do non-metals ions become when they bond with metals?

Answer 7

Negative

Question 8

What happens when sodium and chlorine react?

Answer 8

An electron is transferred from the sodium to the chlroine, forming two oppositely charged ions, which have strong electrostatic attraction for each other.

Question 9

Why does Mg²⁺ O^2- have a higher metling point than Na⁺ Cl^-?

Answer 9

Because MgO has a 2⁺/2- charge which means they have a stronger electrostatic attraction

Question 10

Why do giant ionic substances have high melting/boiling points?

Answer 10

As all the strong electrostatic attraction between the oppositely-charged ions must be broken down throughout the lattice this requires a huge amount of energy.

Question 11

When does a covalent bond form?

Answer 11

A covalent bond forms when two non-metal atoms share a pair of electrons

Question 12

What is a covalent bond?

Answer 12

A covalent bond is the mutual attraction of two nucleii for a shared pair of electrons

Question 13

table showing how many bonds each group forms in a covalent bond

Answer 13

Question 14

What is the simpliest covalent bonded molecule?

Answer 14

H₂

Question 15

Why do simple molecular substances have low melting/ boiling points?

Answer 15

• As the covalent bonds between the atoms within molecules are very strong.
• However the forces of attraction bewteen molecules are relatively very weak.
• These intermolecular forces of attraction therefore require little heat energy to overcome them.

Question 16

What are giant covalent structures?

Answer 16

Giant covalent structures contain many atoms joined together by covalent bonds to form a giant lattice.

Question 17

Why do giant covalent strctures have high metling/boiling points?

Answer 17

As every strong covalent bond must be brken throughout the lattice this requires a huge amount of energy.

Question 18

Why do metals conduct electricty?

Answer 18

• Metals conduct electricity bcause their outer-shell elctrons are free to move and so carry charge.

Question 19

Why and when do ionic compounds conduct electricity?

Answer 19

When their ions become free to move and carry charge, this only happens if they are dissolved (usually in water) or melted.

Question 20

What i metallic bonding?

Answer 20

It is the electrostatic attraction of positevely-charged ions for the “sea” of their delocalised valence electrons.

Question 21

Why are metals malleable and ductile?

Answer 21

This is because they consist of layers of atoms. These layers can slide over one another when the metal is bent, hammered or pressed.

Question 22

What are alloys?

Answer 22

When metals are mixed together to form new metallic substances with new properties.

Question 23

Why does diamond have a high metling point and is very hard?

Answer 23

As each carbon atom is joined to four other carbon atoms, forming a giant covalent structure.

Question 24

Why is graphite softer than diamond and why can it carry charge?

Answer 24

• Each layer is held together only by weak intermolecular forces. The layers are therefore easily seperated.
• Each carbon atom in a layer is joined to only three other carbon atoms. So one of the four outer electrons on each atom is not involved in bonding. These electrons are delocalised.