2.1 - Atomic Structure, Formula and Amounts

Question 1

Atomic Structure

Answer 1

Neutron
- Location = Neucleus
- Charge = 0
- Mass = 1

Proton
- Location = Neucleus
- Charge = +1
- Mass = 1

Electron
- Location = Shells
- Charge = -1
- Mass = 1/1840

Question 2

Isotope

Answer 2

Atoms of the same element with the same number of protons and neutrons but a different number of neutrons in the nucleus
They have the same chemical reactivity as each other as they have the same electronic structure

Question 3

Relative Atomic Mass

Answer 3

The weighted mean mass of one atom of an element compared to 1/12th of the mass of an atom of Carbon 12

Question 4

Relative Molecular Mass

Answer 4

The weighted mean mass of one molecule compared to 1/12th of the mass of an atom of Carbon 12

Question 5

Relative Isotopic Mass

Answer 5

The mean mass of one atom of an isotope compared to 1/12th of the mass of an atom of Carbon 12

Question 6

Mass Spectrometer

Answer 6

• Used to calculate the relative atomic mass of an element
• A sample of the atom is placed into the mass spectrometer
• The device fires this sample at a scale, which detects the different masses of the individual atoms by the force that they hit it with
• The percentage of each mass occurring is the percentage of different isotopes in the sample

Question 7

Acids

Answer 7

Acid: H+ ion donor
Strong Acid: A H+ ion donor which dissociates completely
Weak Acid: A H+ ion donor which dissociates partially

Question 8

Salt

Answer 8

The product of a reaction in which the H+ ions of the acid are replaced my metal ions or ammonium (NH4+) ions

Acid + Alkali –> Salt + Water

Question 9

Advogadro’s Number

Answer 9

6.02*10^23 = The number of particals so that the mass of a substance in grams is equal to its relative atomic mass

Question 10

Mole

Answer 10

6.02*10^23 atoms
The amount of a substance such that its mass in grms is equal to its relative atomic mass

Question 11

Equations

Answer 11

Moles = Mass/Mr
Gas Volume = Moles * 24
Concentration = Moles/Volume
-log[Concentration] = pH

Question 12

Oxidisation Numbers

Answer 12

Oxidation = Loss of electrons
Reduction = Gain of electrons

Oxidisation Number: The + or - number which tells the number of electrons an element has donated or accepted in a chemical reaction

Transition metals use oxidization numbers as roman numerals to tell the number of electrons that that that version of the element gains