Key definitions - Chemistry 1.1

HideShow resource information
Isotopes
are atoms of the same element with different numbers of neutrons.
1 of 35
Atomic (Proton) Number
is the number of protons in the nucleus of an atom.
2 of 35
Mass (Nucleon) Number
is the number of particles (protons and neutrons) in the nucleus.
3 of 35
An ion
is a positively or negatively charged atom or (covalently bonded) group of atoms (a molecular ion).
4 of 35
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 35
Relative atomic mass, Ar
is the weighted mean mass of an atom of an element compared with one-twelfth of the mass of an atom of carbon-12.
6 of 35
Relative molecular mass, Mr
is the weighted mean mass of a molecule compared with one-twelfth of the mass of an atom of carbon-12.
7 of 35
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 35
Amount of substance
is the quantity whose unit is the mole. Chemists use 'amount of substance' as a means of counting atoms
9 of 35
The Avogadro constant, NA
is the number of atoms per mole of the carbon-12 isotope.
10 of 35
A mole
is the amount of any substance containing as many particles as there are carbon atoms in exactly 12g of the carbon-12 isotope.
11 of 35
Molar mass, M
Is the mass per mole of a substance.
12 of 35
The empirical formula
is the simplest whole-number ratio of atoms of each element present in a compound.
13 of 35
A molecule
is a small group of atoms held together by covalent bonds.
14 of 35
The molecular formula
is the actual number of atoms of each element in a molecule.
15 of 35
Molar volume
is the volume of a gas. At room temperature and pressure, the molar volume is approx. 24.0 dm ^3 mol-1.
16 of 35
The concentration of a solution
is the amount of solute in mol, dissolved per 1dm^3(1000cm^3) of solution.
17 of 35
A standard solution
is a solution of known concentration. Standard solutions are normally used in titrations to determine unknown information about another substance.
18 of 35
A species
is any type of particle that takes place in a chemical reaction.
19 of 35
Stoichiometry
is the molar relationship between the relative quantities of substances taking part in a reaction.
20 of 35
An acid
is a species that is a proton donor.
21 of 35
A base
is a species that is a proton acceptor.
22 of 35
An alkali
is a type of base that dissolves in water, forming hydroxide ions OH-(aq) ions.
23 of 35
A 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, NH4+
24 of 35
A cation
is a positively charged ion.
25 of 35
An anion
is a negatively charged ion.
26 of 35
Hydrated
refers to a crystalline compound containing water molecules.
27 of 35
Anhydrous
refers to a substance that contains no water molecules.
28 of 35
Water of crystallisation
refers to water molecules that form an essential part of the crystalline structure of a compound.
29 of 35
An oxidation number
is a measure of the number of electrons that an atom uses to bond with atoms of another element. Oxidation numbers are derived from a set of rules.
30 of 35
Oxidation
is loss of electrons or an increase in oxidation number.
31 of 35
Reduction
is gain of electrons or a decrease in oxidation number.
32 of 35
A redox reaction
is a reaction in which both oxidation and reduction both take place.
33 of 35
A reducing agent
is a reagent that reduces (adds electrons to) another species.
34 of 35
An oxidising agent
is a reagent that oxidises (takes electrons away from) another species.
35 of 35

Other cards in this set

Card 2

Front

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

Back

Atomic (Proton) Number

Card 3

Front

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

Back

Preview of the back of card 3

Card 4

Front

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

Back

Preview of the back of card 4

Card 5

Front

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

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 1.1 resources »