Chemistry A-level (module 2)

What was the order the atom models were produced in?

1. Atomic model

2. Plum pudding model

3. Nuclear model

4. Bohr model

Who was responsible for the atomic model (and what was newly discovered)?

John Dalton (atoms)

Who was responsible for the plum pudding model (and what was newly discovered)?

JJ Thompson (electrons)

Who was responsible for the nuclear model(and what was newly discovered)?

Rutherford (nucleus)

Who was responsible for the Bohr model (and what was newly discovered)?

Niels Bohr (shells)

What is the relative charge (RC) & relative mass (RM) of protons, neutrons and electrons?

Proton:

• RC = 1+

• RM = 1

Neutron:

• RC = 0

• RM = 1

Electron:

• RC = 1-

• RM = 1/1836

What is relative atomic mass?

The average mass of an atom relative to 1/12th of a carbon atom

What is a binary compound?

• 2 elements only

• Metal element comes first

• The ending of the 2nd element changes to -ide

What is a polyatomic ion?

More than one elements make up an ion

What are the first 6 prefixes to use when naming a molecular compound?

1 - mono

2 - di

3 - tri

4 - tetra

5 - Penta

6 - hexa

What is the molecular formula?

The number and type of atoms of each element covalent bonded together in a molecule

What is the empirical formula?

Simplest whole number ration of atoms of each element present in a compound

• always used for ionic compounds

• Some molecular formula can be simplified

How many electrons are in each of the first 4 shells?

1) 2

2) 8

3) 18

4) 32

What is the formula to work out the maximum number of electrons in a shell?

2n²

What is an atomic orbital?

A region around the nucleus that can hold up to 2 electrons with opposite spins

What are the different types of orbitals and is one key difference?

S-, p-, d-, f- orbitals

• their shapes are different

What is the principle quantum number (n)?

The shell number of energy number

What is an electron cloud?

How electrons are found, represented by orbitals

What is the shape of an s-orbital?

Sphere

how many electrons can an s-orbital contain?

2 in each orbital

• starts at n=1

Why can transition metals form multiple ions?

They can lose different amounts of electrons due to their orbitals

What is the shape of a p-orbital?

Dumb bell

How many electrons can a p-orbital contain?

6 in each orbital

• starts at n=2

How many electrons can a d- orbital contain?

10 in each orbital

• starts at n=3

How many electrons can an f-orbital contain?

14 in each orbital

• starts at n=4

What is the electronic configuration of Helium (He)?

1S² (2)

What is the electronic configuration of Neon (Ne)?

1S² 2S² 2P^6 (10)

What is the electronic configuration of argon (Ar)?

1S² 2S² 2P^6 3S² 3P^6 (18)

What 3 elements can be used in the shorthand versions of electronic configurations?

Helium [He], Neon [Ne], Argon [Ar]

What are the 2 conditions for ionic compounds to dissolve in water?

• attraction to solvent must be stronger than the bonds

• Solvent molecules surround ions

What do ideal gasses assume?

• intermolecular forces of attraction are negligible

• Size of gas molecules is negligible compared to size of container

• Random motion and elastic collisions of molecules (no kinetic energy is lost during collisions)

What is Avogadro’s law and what is a good analogy to remember it?

V is proportional to n

• If you want to add more words, you’ll need a bigger book

What is Charle’s law and what is a good analogy to remember it?

V is proportional to T

• if you increase the spacing between words you’ll need a bigger book

What is Boyle’s law and what is a good analogy to remember it?

P is not proportional to V

P is proportional to 1/V

• if an elephant steps on the book, the book will get smaller and words will get closer together

What is Gay-Lussac’s law (aka Amonton’s law) and what is a good analogy to remember it?

P is proportional to T

• if you give the words more energy they’ll try to jump off the page more, putting more pressure on the binding

What is the ideal gas equation (+ units for each)?

PV = nRT

P = pressure (Pa)

V = volume (m³)

n = moles

R = gas constant (8.31 J K^-1 mol^-1)

T = temperature (K)

What is meant by absolute 0 degrees?

0 Kelvin (-273 ° C)

• all particles stop vibrating

• Complete absence of heat energy

What is the definition of concentration?

How much solute is in a known volume of a solution

What is the equation of concentration?

Concentration = moles/ volume

= mass/ volume

What is a standard solution?

A solution of known concentration

What are the standard conditions and what is the volume of 1 mole at these conditions?

RTP - room temperature and pressure

• temp = 20° C

• Pressure = 101 kPa ( 1 atm)

• 1 mole has a volume of 24 dm³

What is the formula for using moles and RTP?

V = moles x RTP

V = dm³

RTP = 24

What kind of pairs of electrons have the greatest repulsion?

Lone pair to lone pair repulsion

What kind of pair of electrons have the weakest repulsion?

Bond pair to bond pair repulsion

What kind of pairs of electrons has the middle repulsion?

Lone pair to bond pair repulsion