# Module 1 Atoms and reactions

UNIT 1 Atoms. Bonds and Groups

HideShow resource information
• Created by: Parmz
• Created on: 13-03-13 20:59

## Isotopes

Are atoms of the same element with different numbers of neutrons.

1 of 32

## Atomic number (proton)

Is the number of protons in the nucleus of an atom.

2 of 32

## Mass number (nucleon)

is the number of particles (protons and neutrons) in the nucleus.

3 of 32

## Ion

Positively or negatively charged atom.

4 of 32

## Relative Isotopic Mass

is the mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12.

5 of 32

## Relative Atomic Mass

Is the weighted mean mass of an atom compared with one twelfth of the mass of an atom of carbon-12.

6 of 32

## Relative Molecular Mass

Is the weighted mean mass of a molecule compared with one-twelfth of the mass of an atom of carbon-12.

7 of 32

## Relative Formula Mass

Is the weighted mean mass of a formula unit compared with one-twelfth of the mass of an atom of carbon-12.

8 of 32

Is the number of atoms per mole of the carbon-12 isotope (6.02 x 10,23 mol -1)

9 of 32

## Mole

Is the amount of any substance containing as many particles as there are carbon atoms in exactly 12g of the carbon-12 isotope.

10 of 32

## Molar Mass

is the mass per mole of a substance. Units: g mol-1

11 of 32

## Empirical Formula

Is the simplest whole-number ratio of atoms of each element present in a compound.

12 of 32

## Molecule

Is a small group of atoms held together by covalent bonds.

13 of 32

## Molecular Formula

Is the actual number of atoms of each element in a molecule.

14 of 32

## Molar Volume

Is the volume per mole of a gas. Units: dm-3 mol-1.

Room temperature approx. 24.0dm3 mol-1

15 of 32

## Concentration

The amount of solute in mol, dissolved per 1dm3 (1000cm3) of solution.

16 of 32

## Standard solution

Is a solution of known concentration. (Usually used in titrations)

17 of 32

## Species

Is any type of particle that takes part in a chemical reaction.

18 of 32

## Stoichiometry

Is the molar relationship between the relative quantites of substances taking part in a reaction.

19 of 32

## Acid

Is a species that is a proton donor

20 of 32

## Base

Is a species that is a proton acceptor

21 of 32

## Alkali

Is a type of base that dissolves in water forming hydroxide ions

22 of 32

## Salt

Is any chemical compound formed from an acid when a H+ ion from the acid has been replaced by a metal ion or another positive ion, such as the ammonium ion.

Cation - positively charged ion

Anion - negatively charged ion

23 of 32

## Hydrated

Contains water molecules

24 of 32

## Anhydrous

Contains no water molecules

25 of 32

## Water of crystallisation

Refers to water molecules that forman essential part of the crystalline structure of a compound.

26 of 32

## Oxidation number

Is a measure of the number of electrons that an atom uses to bond with atoms of another elements.

27 of 32

## Oxidation

Loss of electrons or an increase in oxidation number

28 of 32

## Reduction

Gain of electrons or a decrease in oxidation number

29 of 32

## Redox Reaction

A reaction where both oxidation and reduction take place.

30 of 32

## Reducing Agent

Is a reagent that reduces (adds electron to) another species.

31 of 32

## Oxidising Agent

Is a reagent that oxidises (takes electrons from) another species.

32 of 32