Chapter 2 - Atoms, Ions & Compounds

Question 1

When does fizzing occur in a reaction?

Answer 1

When a gas is released

Question 2

What is the formula of ammonia and ammonium?

Answer 2

Ammonia = NH3
Ammonium = NH4 (+1 charge)

Question 3

What is the relative mass of an electron?

Answer 3

1/1836

Question 4

What is the charge of a proton?

Answer 4

+1.60217733 x 10^-19

Question 5

What is the charge of a neutron?

Answer 5

-1.60217733 x 10^-19C

Question 6

What are positive and negative ions called?

Answer 6

Cation = +
Anion = -

Question 7

What is Mr and Ar relative to?

Answer 7

1/12 mass of a carbon - 12 atom

Question 8

Meaning of weighted mean?

Answer 8

Takes into account the percentage abundance of each isotope and relative isotopic mass of each

Question 9

How does mass spectrometry work?

Answer 9

1. Sample is vaporised
2. Sample is ionise (so it can be detected) to form positive +1 ions (always)
3. Ions are accelerated. Heavier ones move slower than lighter ones
4. When the ions hit the detector, current is produced which forms the mass spectrum graph

Question 10

What are the axis on the mass spectrum graph?

Answer 10

X axis = mass to charge ratio (m/z)
Y axis = abundance (%)

Question 11

What are the 2 differences of isotopes of the same atom?

Answer 11

• different number of neutron
• different mass numbers
• differ t chemical properties

Question 12

When would isotopes have the same chemical properties?

Answer 12

When they have the same number of electrons in the outer shell