OCR Definitions: Atoms, Bonds & Groups

HideShow resource information
  • Created by: Loomy
  • Created on: 12-12-13 12:22
Relative atomic mass (Ar)
The weighted mean/average mass of an atom of an element compared to 1/12th of the mass of an atom of carbon-12
1 of 26
Relative isotopic mass
The mass of an atom of an isotope compared to 1/12th of the mass of an atom of carbon-12
2 of 26
Relative molecular mass (Mr)
The weighted mean/average mass of a molecule compared to 1/12th of the mass of an atom of carbon-12
3 of 26
Relative formula mass (giant structures)
The weighted mean/average mass of a formula unit compared to 1/12th of the mass of an atom of carbon-12
4 of 26
Empirical formula
The simplest whole-number ratio of atoms of each element present in a compound
5 of 26
Molecular formula
The number of atoms of each 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 plus neutrons in the nucleus of an atom
8 of 26
Isotopes
Atoms of the same element with different masses. The isotopes of an element have the same number of protons (and electrons), but different numbers of neutrons
9 of 26
Acid
Releases H+ ions in aqueous solutions
10 of 26
Base
Readily accepts H+ ions from an acid
11 of 26
Alkali
Soluble base that releases OH- ions in water
12 of 26
Oxidation
The loss of electrons; an increase in oxidation number
13 of 26
Reduction
The gain of electrons; a decrease in oxidation number
14 of 26
Disproportionation
The oxidation and reduction of the same element in a redox reaction
15 of 26
First ionisation energy
The energy required to remove 1 electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions
16 of 26
Second ionisation energy
The energy required to remove 1 electron from each 1+ ion in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ions
17 of 26
nth ionisation energy
The energy required to remove 1 electron from each (n-1)+ ion in 1 mole of gaseous (n-1)+ ions to form 1 mole of gaseous n+ ions
18 of 26
Ionic bond
The electrostatic attraction between oppositely charged ions
19 of 26
Covalent bond
A shared pair of electrons
20 of 26
Dative covalent bond
A shared pair of electrons with only one of the atoms contributing both electrons
21 of 26
Electron pair repulsion theory
Electron pairs repel each other and the number (and type) of electron pairs around the central atom determines the shape of a covalent molecule
22 of 26
Electronegativity
A measure of the attraction of a bonded atom for the pair of electrons in a covalent bond
23 of 26
Polar bond
A covalent bond between two atoms with different electronegativities in which the bonded electron pair of one is drawn closer to the more electronegative atom
24 of 26
Polar molecule
A molecule in which the electron density is not equally distributed, resulting in areas of high electron density (δ+) and areas of low electron density (δ-)
25 of 26
Metallic bonding
The electrostatic attraction between positive metal ions and delocalised electrons
26 of 26

Other cards in this set

Card 2

Front

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

Back

Relative isotopic mass

Card 3

Front

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

Back

Preview of the back of card 3

Card 4

Front

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

Back

Preview of the back of card 4

Card 5

Front

The simplest whole-number ratio of atoms of each element present in a compound

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 Range of topics resources »