Salters Chemistry - Unit F331: 'elements Of Life'

Front 1

Avogadro's constant is:

Back 1

6.02x10^23 - the number of particles in 1 mole of a substance

Front 2

Relative atomic mass:

Back 2

The number of times heavier a given atom is than one twelfth of an atom of carbon 12

Front 3

Relative formula mass:

Back 3

Sum of the relative atomic masses of constituent atoms.

Front 4

The empirical formula is:

Back 4

The simplest ratio of atoms of each element in a compound.

Front 5

The molecular formula is:

Back 5

The numbers and types of atoms in a molecule.

Front 6

The atomic number is:

Back 6

The number of protons in an atom of an element.

Front 7

The mass number is:

Back 7

The sum of the number of protons and neutrons in an element.

Front 8

Isotopes are:

Back 8

Atoms with the same atomic number, but different mass numbers. I.e. They have different numbers of neutrons.

Front 9

Radioactivity is:

Back 9

A property of unstable nuclei causing them to emit radiation spontaneously.

Front 10

Alpha radiation:

Back 10

A helium nucleus. +2 relative charge. The nucleus loses two protons and neutrons. It can be stopped by paper, and is not easily deflected by an electrical field.

Front 11

Beta radiation:

Back 11

High energy electrons with charge -1. The nucleus gains a proton and loses a neutron. These can be stopped by foil and deflected by electrical fields.

Front 12

Gamma radiation.

Back 12

A photon with no charge. The nucleus does not change. It takes a lead sheet to stop gamma radiation and cannot be deflected by electrical fields.

Front 13

Half-life is:

Back 13

The time taken for half the radioactive nuclei in a sample to decay OR the time taken for the radioactivity of a sample to reduce to half.

Front 14

Tracers are:

Back 14

Radioactive isotopes whose decay is monitored. Used in medicine for diagnosis. The half-life trace time should not be too long or too short. Tracers are considered relatively safe.

Front 15

Nuclear fusion is:

Back 15

The joining of two or more nuclei to create one more massive nucleus of a new element. Requires high temperatures and/or pressures.

Front 16

An energy level is:

Back 16

A discrete amount of energy an electron in an atomic orbital can possess. Energy levels increase further from the nucleus and get closer together.

Front 17

Absorption spectra are caused by:

Back 17

The absorption of specific frequencies of light by electrons in order to promote them to the next discrete energy level. Delta e = hv.

Front 18

Absorption spectra look like:

Back 18

A series of dark lines on a coloured background, getting closer at higher frequencies.

Front 19

Emission spectra are caused by:

Back 19

The re-emission of specific frequencies of light related to the discrete changed in energy they experience as they drop to lower energy levels. Related by delta e = hv.

Front 20

Emission spectra look like:

Back 20

A series of coloured lines on a dark background getting closer together at high frequencies.

Front 21

Metals and metals form:

Back 21

Metallic bonds.

Front 22

Metals and nonmetals form:

Back 22

Ionic bonds.

Front 23

Nonmetals and nonmetals form:

Back 23

Covalent bonds.

Front 24

Ionic lattices:

Back 24

Ionic bonding. High melting point. Usually soluble. Conductive in solution or if molten.

Front 25

Giant covalent networks:

Back 25

Covalent bonding. High melting point. Insoluble and non- conductive (except graphite)

Front 26

Simple molecular:

Back 26

Covalent bonding. Low melting points and usually insoluble. Non-conductive.

Front 27

Metallic lattices:

Back 27

Metallic bonding, high melting points, insoluble, conductive.

Front 28

Atoms in covalent bonding are held together by:

Back 28

Electrostatic attraction between the nuclei and the shared electrons.

Front 29

Metallic bonding structure:

Back 29

A regular lattice of metal cations surrounded by a sea of delocalised electrons.

Front 30

The shape of a molecule is affected by:

Back 30

The number of electron groups around a central atom. The groups are involved in electrostatic repulsion and arrange themselves as far apart in space as possible.

Front 31

We arrange the periodic table by:

Back 31

Atomic number.

Front 32

Mendeleev arranged the periodic table by:

Back 32

Mass number.

Front 33

Periodicity is:

Back 33

The expression of a regular pattern of properties within a period of the periodic table. The regular pattern is then repeated in other periods.

Front 34

Formula for sulphuric acid:

Back 34

H2SO4

Front 35

Carbonate ions:

Back 35

CO3 2-

Front 36

Sulphate ions:

Back 36

SO4 2-

Front 37

Nitrate ions:

Back 37

NO3 -

Front 38

Ammonium ions:

Back 38

NH4 +

Front 39

Hydrogen carbonate ions:

Back 39

HCO3 -

Front 40

Group 2 metals react with water to give:

Back 40

The metal hydroxide M(OH)2 and hydrogen gas. Hydroxide may be solid or aqueous.

Front 41

Group 2 oxides react with water to give:

Back 41

A metal hydroxide.

Front 42

Group 2 oxides react with acids to give:

Back 42

A metal salt (aq) and water.

Front 43

Group 2 hydroxide solubility:

Back 43

Increases down the group.

Front 44

Group 2 carbonate solubility:

Back 44

Decreases down the group.

Front 45

Group 2 carbonates MCO3 decompose thermally to give:

Back 45

Metal oxide and carbon dioxide.

Front 46

Group 2 carbonates thermal stability:

Back 46

Increases down the group.

Front 47

The sample inlet

Back 47

Stage 1. Where sample is injected. May need to be vaporised if solid.

Front 48

The ionisation area

Back 48

Stage 2. CATIONS are made from molecules with an electron gun.

Front 49

Acceleration area

Back 49

Stage 3. Ions are accelerated to the same kinetic energy by an ELECTRIC field.

Front 50

Drift region

Back 50

Stage 4. A long vacuum in which ions travel and separate. Heavy ions take longer.

Front 51

Ion detector:

Back 51

Stage 5. Where ions are converted into a mass spectrum based on time of flight. Only positive ions are detected.

Front 52

The most massive peak on a mass spectrum is:

Back 52

The molecular ion.

Front 53

The highest peak on a mass spectrometer is:

Back 53

The base peak.

Front 54

Radiocarbon dating can be affected by:

Back 54

The addition of contaminants. The amount of carbon 12 in the formative atmosphere or geography. Provided the sample was not melted and reformed.

Front 55

What is meant by 'one mole' in terms of Avogadro's constant?

Back 55

The number of carbon 12 atoms in 12 grams of carbon 12: 6.02x10^23. This number if atoms in any mole of a substance.

Front 56

Features of an emission spectrum: (3)

Back 56

A series of lines (spectrum); coloured lines on a dark background; lines CONVERGE at HIGHER FREQUENCY.

Front 57

Periodicity is:

Back 57

The recurring trends in elemental properties seen in periods which are repeated in other periods.

Front 58

Elements of the same group have similar properties because of:

Back 58

The same number of electrons in their outer shells, hence they enter similar reactions.

Front 59

Group two hydroxide and carbonate solubility trends down the group:

Back 59

more soluble, less soluble.