Chapter 2 (approved)

Question 1

What is the definition of relative atomic/isotopic mass?

Answer 1

Relative atomic/isotopic mass is the weighted mean mass compared to 1/12 of the mass of a carbon-12 atom.

Question 2

What is an isotope?

Answer 2

A different form of the same element with the same number of protons but a different number of neutrons

Question 3

Why do isotopes of the same element display the same chemical characteristics?

Answer 3

• This is because they have the same number of outer shell electrons
• Therefore they take part in similar chemical reactions

Question 4

How does the physical properties of isotopes change with boiling point?

Answer 4

• Isotopes have a different number of neutrons, which add mass to the atom
• Therefore different isotopes have different physical properties such as boiling point, melting point and density

Question 5

What is relative mass?

Answer 5

The relative mass is the mass of an atom compared to 1/12ish of the mass of a carbon-12 atom

Question 6

How to calculate the weighted mean mass of an element

Answer 6

Multiply the mass number of each isotope of the element by its percentage abundance (decimal form) and add them all together

Question 7

How does the number of neutrons in an element affect the chemical reactions?

Answer 7

No effect

Question 8

What is special about transition metals ionising?

Answer 8

They can form ions with several different charges e.g. copper can form Fe2+ and Fe3+

Question 9

Ammonium: Chemical formula, charge

Answer 9

NH4+, 1+

Question 10

Nitrate: Chemical formula, charge

Answer 10

NO3- , -1

Question 11

Carbonate: chemical formula, charge

Answer 11

CO3 2-, -2

Question 12

Sulfate

Answer 12

SO4 2-

Question 13

Phosphate

Answer 13

PO4 3-

Question 14

Nitrite

Answer 14

NO2 -

Question 15

Sulfite

Answer 15

SO3 2-

Question 16

Nitric acid formula

Answer 16

HNO3