2A - Atoms & Redox definitions Flashcards Preview

AS Chemistry > 2A - Atoms & Redox definitions > Flashcards

Flashcards in 2A - Atoms & Redox definitions Deck (13):
1

Isotope

Atoms of the same element with different number of neutrons and different masses

2

Atomic number

The number of protons in the nucleus of an atom

3

Mass number

The number of particles (protons and neutrons) in the nucleus

4

Ion

A positively or negatively charged atom (or covalently bonded) group of atoms (a molecular ion)

5

Relative isotopic mass

The mass of an atom of an isotope compared with 1/12th of the mass of an atom of carbon-12

6

Relative atomic mass

(Ar)

The weighted mean mass of an atom of an element compared with 1/12th of the mass of an atom of carbon-12

7

Relative molecular mass

The weighted mean mass of a molecule compared with 1/12th of the mass of an atom of carbon-12

8

Relative formula mass

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

9

1st Ionisation energy

The energy required to remove 1 mole of electrons from 1 mole of gaseous atoms from 1 mole of gaseous 1+ ions

10

Electron transfer: Oxidation and reduction

Oxidation = loss of electrons

Reduction = gain of electrons

11

Oxidation numbers to explain redox: Oxidation / reduction

Oxidation = Increase in an oxidation number (more +VE)

Reduction = Decrease in an oxidation number (less +VE)

12

Iso-electronic 

Example?

Ions that have the same number of electrons

E.G.

Al3+ and F- both have 10 electrons

13

Electron shielding

The repulsion between electrons in different inner shells. Shielding reduces the net attractive force from the positive nucleus on the outer-shell electrons