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Flashcards in THE ATOM AND REDOX 2A Deck (28)
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1

Definition of atomic number

The number of protons in the nucleus of one atom of an element

2

Definition of an isotope

An atom of the same element that has the same number of protons but different number of neutrons

3

How to work out the mass number

The number of protons plus the number of neutrons

4

Definition of relative isotopic mass

The mass of one atom of an isotope compared to 1/12 the mass of one atom of carbon-12

5

Why is carbon-12 the standard

It can be obtained in an isotopically pure state and is unreactive

6

Definition of relative atomic mass

The weighted average mass of one atom of an element compared to 1/12 the mass of one atom of carbon-12

7

Definition of relative molecular mass (Mr)

The weighted mean mass of a molecule compared to 1/12 the mass of 1 atom of carbon-12

8

Definition of relative formula mass (Mr)

The weighted mean mass of a formula unit compared to 1/12 the mass of 1 atom of carbon-12

9

Definition of 1st ionisation energy

The amount of energy needed to remove 1 electron from each atom in 1 mole of gaseous atoms to form one mole of gaseous 1+ ions

10

What are shielding electrons?

The electrons between the nucleus and other electron shells

11

State and explain the general trend of first ionisation energy across period 2

The IE increases. The charge in the nucleus increases because the proton number increases and the number of shielding electrons stays the same therefore the overall electrostatic attraction is stronger so the IE is larger. The atomic radius is also slightly smaller.

12

How many s orbitals are there?

1

13

How many p orbitals are there?

3 - px, py, pz

14

How many d orbitals are there?

5

15

How many f orbitals are there?

7

16

What is the term used for subshells that are of identical energy?

Degenerate

17

Definition of oxidation

loss of electrons/gain of oxygen/loss of hydrogen

18

Definition of reduction

gain of electrons

19

Definition of oxidising agent

A reagent that oxidises another species and is reduced in the process

20

Definition of reducing agent

A reagent that reduces another species and is oxidised in the process

21

What is the term used to describe when the same substance is both reduced and oxidised?

Disproportionation

22

Definition of orbital

Region of space that can hold up to 2 e- with opposite spin (and the same energy)

23

Rules of oxidation number: Group 1 elements

Have an O.N of +1

24

Rules of oxidation number: Group 2 elements

Have an O.N of +2

25

Rules of oxidation number: Fluorine atoms

Have an O.N of -1

26

Rules of oxidation number: Oxygen atoms

Have an O.N of -2 except when in a peroxide

27

Rules of oxidation number: Hydrogen atoms

Have an O.N of +1 except when in a hydride

28

Definition of molar mass

The mass per mole of a substance. The units of molar mass are g mol⁻¹