2: Atomic structure

Question 1

Define relative isotopic mass

Answer 1

The mass of an isotope relative to 1/12th of the mass of an atom of carbon-12

Question 2

Define relative atomic mass

Answer 2

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

Question 3

What is the standard mass for atomic mass?

Answer 3

The standard mass for atomic mass is 1u which is the mass of 1/12th of an atom of carbon.

So, 1u is approximately the mass of a proton or neutron

Question 4

How many mass units is carbon-12?

Answer 4

12 mass units (12u)

Question 5

What does the weighted mean mass take account of?

Answer 5

The percentage abundance of each isotope
The relative atomic mass of each isotope

Question 6

Ionic formula for ammonium

Answer 6

NH4 2-

Question 7

Ionic formula for hydroxide ion

Answer 7

OH-

Question 8

Ionic formula for a nitrate ion

Answer 8

NO3 -

Question 9

Ionic formula for a carbonate ion

Answer 9

CO3 2-

Question 10

Ionic formula for a sulfate ion

Answer 10

SO4 2-

Question 11

What is meant by the term anhydrous?

Answer 11

Containing no water molecules.

Question 12

What is meant by the term anion?

Answer 12

A negatively charged ion with more electrons than protons.