C2a- Bonding and Calculations

Question 0

What is the structure of an ionic compound?

Answer 0

Regular lattice

Always have giant ionic lattice arrangement

Question 1

Why do simple molecular substances not conduct electricity?

Answer 1

There are no ions so no electrical charge.

Question 2

What is a double covalent bond?

Answer 2

When 2 pairs of electrons are shared. For example in oxygen gas (02)

Question 3

What is the mass number?

Answer 3

Total number of protons and neutrons

Question 4

What is an isotope?

Answer 4

Different atomic forms of the same element, which have the same number of protons but different number of neutrons

Question 5

What is the atomic number?

Answer 5

Number of protons (and therefore electrons)

Question 6

What type of bonding do group 1 elements do?

Answer 6

Ionic- lose one election from outer shell.

Question 7

What are the forces like in an ionic compound?

Answer 7

Very strong electrostatic forces of attraction between oppositely charged ions, in all directions

Question 8

Ionic bonding is…….

Answer 8

Transferring electrons to form ions which are then strongly attracted to each other

Question 8

Why is diamond hard?

Answer 8

Each carbon atom has 4 covalent bonds in a very rigid giant covalent structure.

Question 9

In giant covalent structures the bond between atoms is….

Answer 9

Strong covalent bonds

Question 10

Do giant covalent structures conduct electricity?

Answer 10

No

Except for graphite

Question 11

Group 1 elements (alkali metals) form ionic compounds with …….

Answer 11

Non metals

Question 13

What are the properties of ionic compounds?

Answer 13

High melting and boiling points due to the strong attraction between ions.

Carry electric current when melted as ions are free to move

Dissolve in water. Ions free to move so carry electric current

Question 16

In methane (CH4) carbon has 4 outer electrons. So it forms ….. Covalent bonds with hydrogen to form methane

Answer 16

4

Question 17

There are 2 types of covalent substances, what are they?

Answer 17

Simple molecular

Giant covalent

Question 19

Why can graphite conduct electricity even though it is a giant covalent structure and a non metal?

Answer 19

As each carbon atom has one delocalised electron.

Question 20

What 2 ways can you make an ionic compound carry an electric current?

Answer 20

Dissolve in water

Melt

Question 22

What is the melting and boiling point of simple molecular substances like and why?

Answer 22

Very low due to weak intermolecular forces which can be easily broken.

Question 23

Why are most simple molecular substances gas or liquid at room temp?

Answer 23

Weak intermolecular forces

Question 24

Isotopes must have the same ………. number but different ……….. numbers.

Answer 24

Atomic

Mass

Question 25

Give 3 examples of giant covalent structures

Answer 25

Diamond
Graphite
Silicon dioxide

Question 26

Why can layers of graphite slide over each other?

Answer 26

Each carbon atom only forms 3 covalent bonds, which creates layers which a free to slide over each other. As there are weak intermolecular forces between the layers.

Question 27

What is the melting/boiling point of a giant covalent structure like?

Answer 27

Very high due to the strong covalent bonds between atoms

Question 29

What is a covalent bond?

Answer 29

Atoms share electrons (a pair) to become stable

Question 30

Each covalent bond provides how many extra electrons for each atom?

Answer 30

1

Question 33

Giant covalent structures are similar to ionic structures (lattices) except that there are no……. ……

Answer 33

Charged ions

Question 38

In simple molecular substances, what are the forces of attraction like and why?

Answer 38

Between molecules- very weak. However very strong covalent bonds.