Chemistry Unit 1 definitions

?
  • Created by: ava.scott
  • Created on: 13-04-14 12:46
Relative Atomic Mass (Ar)
The weighted average mass of an atom compared to one-twelfth of the mass of an atom of carbon-12.
1 of 26
Relative isotopic mass
The weighted average mass of an isoptope compared to one-twelfth of the mass of a carbon-12 atom.
2 of 26
Relative Molecular Mass (Mr)
The weighted average mass of a molecule compared to one-twelfth of the mass of a carbon-12 atom.
3 of 26
Relative formula mass (
The weighted average mass of a formula unit compared to one-twelfth of the mass of a carbon-12 atom.
4 of 26
Empirical Formula
The simplest whole number ratio of atoms of each element in a molecule
5 of 26
Molecular Formula
The actual number of each atom of an element in a molecule.
6 of 26
Atomic number
The number of protons in the nucleus of an atom.
7 of 26
Mass Number
The number of protons and neutrons in the nucleus of an atom.
8 of 26
Isotopes
Different versions of an element with varying atomic mass/ number of neutrons.
9 of 26
Acid
A H+ donator in aqueous solution.
10 of 26
Base
Accepts H+ ions from an acid
11 of 26
Alkali
A OH- donator in aqueous solution
12 of 26
Oxidation
The loss of electrons from a molecule/atom, resulting in positive charge.
13 of 26
Reduction
The gain of electrons in a molecule/atom, resulting in negative charge.
14 of 26
Disproportionation
The oxidation and reduction of the same element within one redox reaction.
15 of 26
1st Ionisation energy
The energy needed to remove 1 mole of electrons from 1 mole of atoms in their gaseous state, to produce 1 mole of +1 ions.
16 of 26
2nd Ionisation energy
The energy needed to remove 1 mole of electrons from 1 mole of +1 ions in their gaseous state to produce 1 mole of +2 ions.
17 of 26
nth ionisation energy
The energy require to remove 1 mol of electrons from 1 mole of (n-1) ions in their gaseous state to form 1 mole of n+ ions.
18 of 26
ionic bond
where a metal donates its electrons to a non-metal, forming two oppositely charged ions.
19 of 26
Covalent bond
Where two non-metals share a pair of electrons to complete their outer shells
20 of 26
Dative Covalent Bond
when one atom donates both electrons to the shared electron pair
21 of 26
Electron pair repulsion theory
Electron pairs repel eachother and the number and type of electron pairs surrounding the central atom in a molecule determines its molecular shape.
22 of 26
Electronegativity
A measure of the attraction a atom has for the bonded pair of electrons across a covalent bond.
23 of 26
Polar Bond
Where the more electronegative atoms pulls the electrons to it, resulting in a negative charge at that end, and a positive charge at the other e.g. HCl
24 of 26
Polar Molecule
A molecule in which electron density is not equally distributed resulting in regions with negative and positive charge e.g. H2O, NH3
25 of 26
Metallic bonding
The electrostatic attraction between protons and delocalised electrons.
26 of 26

Other cards in this set

Card 2

Front

The weighted average mass of an isoptope compared to one-twelfth of the mass of a carbon-12 atom.

Back

Relative isotopic mass

Card 3

Front

The weighted average mass of a molecule compared to one-twelfth of the mass of a carbon-12 atom.

Back

Preview of the back of card 3

Card 4

Front

The weighted average mass of a formula unit compared to one-twelfth of the mass of a carbon-12 atom.

Back

Preview of the back of card 4

Card 5

Front

The simplest whole number ratio of atoms of each element in a molecule

Back

Preview of the back of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all ALL TOPICS IN UNIT 1 resources »