Ionic compounds

Question 1

what is an ion?

Answer 1

charged particle formed when an atom loses or gains electrons

Question 2

what do metal/ non metal atom lose/gain to form ions? and what type?

Answer 2

• metal atoms lose electrons to form positively charged ions (cations)
• non-metal atoms gain electrons to form negatively charged ions (anions)

Question 3

why are ionic bonds formed?

Answer 3

The oppositely charged ions are strongly attracted to each other, forming ionic bonds.

Question 4

what can be used to model the transfer of electrons?

Answer 4

a dot and cross diagram

Question 5

what are ions arranged in?

Answer 5

regular, repeating arrangement called an ionic lattice

Question 6

why is the lattice formed?

Answer 6

the ions attract each other and form a regular pattern with oppositely charged ions next to each other.

Question 7

what is the ionic lattice held by?

Answer 7

ionic bonds

Question 8

in three-dimensional models, what are ionic bonds shown as?

Answer 8

straight lines between ions.

Question 9

what are ionic bonds (as a force)?

Answer 9

strong electrostatic forces between oppositely charged ions.

Question 10

what are ionic compounds at room temperature?

Answer 10

solids

Question 11

what are Melting and boiling?

Answer 11

state changes

Question 12

what must happen in order to melt or boil an object? and why?

Answer 12

• energy has to be transferred to a substance in order to melt or boil it.
• energy is needed to break the bonds between particles in the substance

Question 13

what happens to bonds during melting and boiling?

Answer 13

• some bonds are overcome during melting

- all remaining bonds are overcome during boiling

Question 14

what is the correlation between the melting and boiling point and the energy needed?

Answer 14

The more energy needed, the higher the melting point or boiling point.

Question 15

why do ionic compounds have high melting and boiling points? (2)

Answer 15

• ionic lattice contains large number of ions,
• lots of energy is needed to overcome these ionic bonds
• so ionic compounds have high melting and boiling points

Question 16

A substance can conduct electricity if:

Answer 16

it contains charged particles, and

these particles are free to move from place to place

Question 17

how do ionic compounds conduct electricity? (2)

Answer 17

when molten to form a liquid or dissolved in water to form an aqueous solution.

Question 18

why do we melt/ dissolve ionic compounds to make them conduct electricity?

Answer 18

This is because both processes make their ions free to move from place to place

Question 19

why can ionic compounds not conduct electricity when solid?

Answer 19

their ions are held in fixed positions and cannot move.

Question 20

what are ionic compounds when solid?

Answer 20

insulators

Question 21

what must a formula for an ionic compound contain? and why?

Answer 21

-same number of positive and negative charges so that the charges are balanced and it is neutral overall.

Question 22

what are ployatomic ions?

Answer 22

ions formed from groups of atoms

Question 23

what does it mean when an ionic compound ends in -ide?

Answer 23

-ide if it contains just two elements

Question 24

what does it mean when an ionic compound ends in -ate?

Answer 24

-ate if it contains three or more elements, one of which is oxygen