Test 2

Question 1

Periodic Table

Answer 1

• Arrangement of known elements
• Organised in a way that HIGHLIGHTS period nature of they repeating properties
• Elements arranged into ROWS in order of INCREASING ATOMIC NUMBER
• Also arranged into COLUMNS according to SIMILAR CHEMICAL PROPERTIES

Question 2

Periods

Answer 2

• HORIZONTAL ROWS
• In order of INCREASING atomic number
• 7 Periods

Question 3

Groups

Answer 3

• VERTICAL COLUMNS
• In order of SIMILAR chemical properties
• 18 Groups

Question 4

Periodic Trends

Answer 4

• (LEFT TO RIGHT) Metallic to Non Metallic

- TOP TO BOTTOM in any GROUP the physical and chemical properties remain SIMILAR but INCREASE in metallic nature

Question 5

HALOGENS

Answer 5

• Reactive Non Metals
• Produce Ionic compounds with metals eg. CaCl2, AlBr3, NaF
• Group 17

Question 6

NOBLE GASES

Answer 6

• Non Metals
• Low chemical reactivity
• Group 18

Question 7

ALKALI METALS

Answer 7

• Group 1
• All soft low melting point metals
• React vigorously with water access to produce hydrogen gas
• Alkali Metals compounds are all ionic with the elements always forming +1 ions eg. LiCl, Na2S, K3PO4

Question 8

ALKALI EARTH METALS

Answer 8

• Group 2
• React strongly with acids producing hydrogen gas
• Also react with water, producing a metal hydroxide and hydrogen has
• Compounds are ionic, with metals always forming +2 e.g.. MgCl2, CaS and Sr3(PO4)2

Question 9

METAL ELEMENTS PROPERTIES

Answer 9

• Good conductors of electricity
• Good conductors of heat
• Malleable and ductile
• Shiny (when scratched)
• Solids at room temperature (except mercury)

Question 10

NON METAL ELEMENT PROPERTIES

Answer 10

• Poor conductors of electricity
• Poor conductors of heat
• Most are gases at room temperature
• Solid non metals are BRITTLE AND HARD

Question 11

QUANTUM MECHANICAL MODEL OF ELECTRON ARRANGEMENT

Answer 11

• Valence electrons on shells

- (2,8,8,18)

Question 12

VALENCE ELECTRONS

Answer 12

• Electrons on the outermost shell

Question 13

IONISATION

Answer 13

• Measure of how strongly an element holds onto its electrons
• Affects an elements tendency to form positive or negative ions

Question 14

IONISATION - ATOMS NUCLEAR CHARGE TREND

Answer 14

• Nuclear charge depends upon the number of protons in the nucleus
• Greater nuclear charger, greater number of electrons attracted STRONGLY to the nucleus
• Which means the ionisation energy increases with increasing nuclear charge

Question 15

IONISATION - DISTANCE BETWEEN NUCLEUS AND OUTERMOST ELECTRON (ATOMIC RADIUS)

Answer 15

• As atomic radius increases so the STRENGTH OF ATTRACTION between the nucleus and outer electron
• Ionisation energy decreases with increasing atomic radius

Question 16

IONISATION - SHIELDING BY INNER ELECTRON

Answer 16

• Each electron in the atom’s electron cloud REPELS each other electron
• The more electrons there are between the outer electron and the nucleus THE MORE EASILY the electron is removed
• Also means LOWER IONISATION ENERGY

Question 17

ATOMIC RADIUS

Answer 17

• The DECREASE in atomic radius that occurs for elements FURTHER RIGHT in the periodic table
• DECREASE IN ATOMIC RADIUS is due to the atomic increasing nuclear charge
• High nuclear charge (POSITIVE) increases the attraction of electrons which brings them CLOSER TO THE NUCLEUS resulting in a DECREASE IN ATOMIC RADIUS
• Atoms further to the right in a period show a DECREASE in in the size measured by their ATOMIC RADIUS

Question 18

INCREASING ATOMIC RADIUS

Answer 18

• Trend of INCREASING ATOMIC RADIUS down any group of the periodic table is due to the higher SHELL NUMBER OF ELECTRONS
• Higher number of shells are further away from the nuclear so atoms further down the group will have LARGE RADIUS

Question 19

ELECTRONEGATVITY

Answer 19

• The ability of an atom in a molecule to attract electrons to itself
• Caesium has the LOWEST electronegativity
• Fluorine has the HIGHEST electronegativity
• Non metals have the highest values of it, as these elements gain electrons to form negative ions
• Metals have low electronegativity

Question 20

METALLIC PROPERTIES

Answer 20

• LOW ionisation energy is essential is atoms want to form the positive ions required for METALLIC STRUCTURE (unique physical properties)
• Only found on the left side of the periodic table, as they have LOW IONISATION ENERGY
• Ionisation energies decreases down
• group elements metallic properties increase

Question 21

METALLIC - REDUCING AGENTS

Answer 21

• Lose electrons and become oxidised in substances like ACIDS, WATER AND OXYGEN
• Associated with low ionisation energy

Question 22

NON METAL PROPERTIES

Answer 22

• High hardness
• Brittleness
• High melting points
• High boiling points
• Semi conducting and non electrical conductivity

Question 23

UPPER RIGHT PERIODIC TABLE

Answer 23

• Highest ionisation
• Highest electronegativity
• Most valence electrons

Question 24

ELECTRON CONFIGURATON

Answer 24

• The electron configuration of an atom or ion shows the shells (1,2,3,4 …) containing electrons and the number of electrons in each of these shells
• Order in which electrons fill the available shells follows a general pattern where electrons fill the lowest numbered shells first

Question 25

VALENCE ELECTRONS AND BONDING CAPACITY

Answer 25

• Strong relationship between the elements group number and its ionic bonding capacity
• Strong relationship between an elements covalent bonding capacity and its group number

Question 26

ELECTRON CONFIGURATION AND ION FORMATION

Answer 26

• Atoms form ions by gaining or losing electrons
• Positive electrons have fewer electrons whilst negative ions have more electrons than the ORIGINAL ATOM
• Means electrons configurations of an atom and its ion must be different
• Usually the ion will have an electron configuration like that of the nearest noble gas

Question 27

MASS SPECTROMETRE

Answer 27

• Analytical tool that can be used to determine relative molecular mass and molecular structure of complex organic compounds
• Its used to determine the relative atomic mass of the isotopes of an element

Question 28

OPERATION OF MASS SPECTROMETER

Answer 28

• Vaporisation; of the sample to be analysed
• Ionisation; of the vapourised sample
• Acceleration; and separation of the resulting ions based on their mass to charge ratio
• Detection; or counting the number of each of the ions of different mass to charge ratio

Question 29

HOW THE OPERATION WORKS

Answer 29

• Sample of chosen element is vaporised in a vacuum chamber then passed into the mass spectrometer
• Here is passes through A HIGH ENERGY ELECTRON BEAM where collisions within the beam cause the gaseous atoms to lose one of their electrons to form +1 ions
• Resulting ions are then accelerated by an ELECTRIC FIELD to form a high speed beam of positive ions directed through a STRONG MAGNETIC FIELD
• Individual ions become deflected by the field and move into circular paths of different radius
• Detector measures the intensity and radius of deflection of the ion beams
• Detector count is a measure of the isotope abundance
• Resulting data can be displayed as a mass spectrum of the sample