2 - Atoms, Ions and Compounds

Question 1

What is Sulphate and it’s Charge?

Answer 1

. (-2)
S O
4

Question 2

What is Nitrate and it’s Charge?

Answer 2

. (1-)
N O
3

Question 3

What is Hydroxide and it’s Charge?

Answer 3

. (1-)
OH

Question 4

Give the formulae for Aluminium Sulphate?

Answer 4

Al wants to get +3
SO4 has a charge of -2

So Al x 2 and SO4 x 3

Al2(SO4)3

Question 5

What is Carbonate and it’s Charge?

Answer 5

. (2-)
CO
3

Question 6

What is Ammonium and it’s Charge?

Answer 6

. (1+)
NH
4

Question 7

What is Zinc ion and it’s Charge?

Answer 7

. (2+)
Zn

Question 8

What is Silver ion and it’s Charge?

Answer 8

. (1+)
Ag

Question 9

What is the formula of potassium sulphate?

Answer 9

Sulphate ion (SO4) has a charge of -2.
Potassium forms a charge of +1

So for every one sulfate ion you need two potassium ions to cancel out the charges.
Formula = K2SO4

Question 10

Charges on an ionic compound must always balance out to what?

Answer 10

Zero.

Question 11

What are ions?

Answer 11

A positively or negatively charged atom or a group of atoms, where the number of electrons is different from the number of protons.

Question 12

How are ions formed?

Answer 12

When electrons are transferred from one atom to another.

Question 13

What are cations?

Answer 13

Positive ions, fewer electrons than protons.

Question 14

What are anions?

Answer 14

Negative Ions, atoms with more electrons than protons.

Question 15

What does (aq) state symbol mean?

Answer 15

Dissolved in water

Question 16

What is the definition for the Relative Atomic Mass?

Answer 16

The weighted mean mass of an atom of an element, compared to 1/12 th of the mass of an atom of carbon-12.

Question 17

What is a binary compound?

Answer 17

A compound that contains only two element.

Question 18

What is the definition for Relative Isotopic Mass?

Answer 18

The mass of an atom of an isotope, compared with 1/12 th of the mass of an atom of carbon-12.

Question 19

What is the difference in type of number for the relative atomic mass and relative isotopic mass?

Answer 19

RAM is an average so is not usually a whole number.

RIM is usually a whole number. (One mass)

Question 20

What is an isotope?

Answer 20

Isotope of an element are atoms with the same number of protons but different number of neutrons.

Question 21

When is the relative molecular mass used and when the relative formula mass is used?

Answer 21

Relative Molecular Mass - simple molecules
Relative Formula Mass - compounds with giant structures (ionic and giant covalent)

Question 22

What is a mass spectra used for?

Answer 22

To work out the relative atomic masses of different elements.

Question 23

On a Mass Spectrum what is on the y-axis and x-axis?

Answer 23

Y-axis: % abundance of ions

X-axis: Mass/Charge (relative isotopic mass)