Topic 1: Atomic Structure and the Periodic Table (part 1)

What are the subatomic particles in an atom?

Neutrons, proton and electron

What is the charge and mass of a neutron?

Charge= 0, Mass= 1

What is the charge and mass of a proton?

Charge= +1, Mass= 1/1840

What is the charge and mass of an electron?

Charge= -1, Mass= 1

Where is the neutron located?

Nucleus

Where is the proton located?

Nucleus

Where is the electron located?

Shell

What does the top number of an element in the PT show?

Mass number

What does the bottom number of an element in the PT show?

Atomic number

What does the period (row) represent?

The number of electron shells

What does the group number (columns) represent?

Number of electrons in the outer shell

Define “ion”.

A charged particle formed when an atom gains or loses electrons.

Do the number of protons and neutrons change in an ion?

no

What goes first when naming ionic compounds?

metal

What does the ionic compound end in if the anion contains one element?

ide

What does it mean if the anion in the ionic compound ends in “ate”?

contains two elements and one is oxygen (except for hydroxide)

Ionic formula for ammonium?

NH₄⁺

Ionic formula for silver?

Ag⁺

Ionic formula for hydrogen?

H⁺

Ionic formula for oxide?

O^2-

Ionic formula for carbonate?

CO₃^2-

Ionic formula for hydroxide?

OH^-

Ionic formula for sulfate?

SO₄^2-

Ionic formula for sulfide?

S^2-

Ionic formula for nitrate?

NO₃^-

Ionic formula for nitride?

N^3-

Ionic formula for phosphate?

PO₄^3-

Define the term ‘isotope’.

Atoms of the same element with the same number of protons and electrons but a different number of neutrons

Define ‘Relative Atomic Mass’

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

Define ‘Relative Isotopic Mass’

The mass of an individual atom of a particular isotope compared to 1/12g of the mass of an atom of carbon-12

Define ‘Relative Formula Mass’.

The sum of the relative atomic masses (Ar) of all atoms in the formula.

What is the process of the Mass Spectrometer?

1. Injection sample is injected into vaporisation chamber.

2. Vaporisation: sample is vaporised (heated to form a gas).

3. Ionised sample is bombarded with high energy from an electron gun/filament → This knocks an electron off the atoms to form positively charged ions.

4. Acceleration ions are accelerated through a slit by an electric field.

5. Deflection ions are deflected by a magnetic field.

6. Detection: ions collide with a detector, which is connected to a computer. This generates a mass spectrum.

What do mass spectrometers run under?

Vacuum

Why must the sample be vaporised?

Particles can move freely.

Why must particles be ionised?

So it can experience an electrical & magnetic field.

Why must there be a vacuum in the mass spectrometer?

So there is no air so no particles for ions to collide with.

What does the amount of deflection for a given sideways force depend on?

Mass

Does heavier or lighter objects get deflected more?

lighter

Where does the magnetic field start in a mass spectrometer?

At the longer magnet

What isotopes does chlorine exist as?

¾ ³⁵Cl and ¼ ³⁷Cl

What is the molecular ion peak?

The peak with the greatest m/z value. It indicates the molecular mass of the molecule.