M3 - Periodicity, Groups 2 and 7

Question 2

Answer 2

C

Question 3

Are halogens oxidising or reducing agents?

Answer 3

Oxidising agents, as they themselves are reduced (electron acceptors)

Question 4

Answer 4

A

Question 5

Why are giant covalent lattices insoluble?

Answer 5

Covalent bonds holding it together are too strong to be broken by interaction with solvents.

Question 6

What are the properties of giant covalent lattices?

Answer 6

High melting and boiling points
Insoluble in almost all solvents
Do not conduct (except for graphite and graphene)
formed from carbon, silicon anf boron

Question 7

How were the elements ordered by Mendeleev?

Answer 7

Increasing atomic mass

Question 8

Answer 8

B

Question 9

what is produced when Ba is added to water?

Answer 9

Barium hydroxide and hydrogen gas

Question 10

what is the colour of iodine in an organic solvent?

Answer 10

Purple

Question 11

What is the name for the horizontal rows of the periodic table?

Answer 11

Periods

Question 12

Define First Ionisation Energy (2)

Answer 12

The energy required to remove one electron from each atom (1) in one mole of gaseous atoms to form one mole of gaseous 1+ ions (1)

Question 13

What causes the large jumps in successive ionisation energies?

Answer 13

Moving down to a closer shell, as these electrons are closer so experience a greater nuclear attraction.

Question 14

What block is Lithium placed in and why?

Answer 14

Li is an S-block element - A s-block element has its highest energy/outermost electron in a s subshell/orbital

Question 15

What is ionisation?

Answer 15

The removal of one or more electrons from an atom.

Question 16

Which is the most reactive halogen and why?

Answer 16

Fluorine, as it has a small atomic radius and less shielding. Easier for fluorine to gain a electron

Question 17

Why does ionisation energy increase across a period?

Answer 17

The number of protons in the nucleus increases so nuclear charge increases causing atomic radius to decrease, whilst shielding stays the same.

Question 18

Complete the word equation;
HEAT
Calcium carbonate ->

Answer 18

Calcium oxide and carbon dioxide

Question 19

How does electron shielding affect ionisation energy?

Answer 19

Inner shell electrons repel outer shell electrons, called shielding. This reduces the attraction between the nucleus and the outer electrons. therefore lower ionisation energy

Question 20

In period 2, explain the fall of ionisation energy from nitrogen to oxygen

Answer 20

Nitrogen’s electrons in the 2p sub shell are unpaired so oxygen’s 8th electron is paired, causing repulsion and a lower ionisation energy.

Question 21

what is the colour of aqueous chlorine?

Answer 21

Pale green

Question 22

Why do most giant covalent lattices not conduct electricity?

Answer 22

All four outer shell electrons are involved in covalent bonding. No mobile charge carriers.

Question 23

How does atomic radius affect ionisation energy?

Answer 23

Greater distance between the nucleus and outer electrons, the attraction is lower.

Question 24

Explain the trend of first ionisation energy down a group

Answer 24

Atomic radius increases,
More shells so shielding increases,
Nuclear attraction on outer electrons decreases,
First ionisation energy decreases.

Question 25

What is Successive Ionisation Energy?

Answer 25

A measure of the energy required to remove each electron in turn

Question 26

In period 2, explain the fall from beryllium to boron of first ionisation energies

Answer 26

The new electron enters the 2p sub shell, which is slightly further away from the nucleus than the 2s sub shell.

Question 27

What are common properties of metals?

Answer 27

Strong metallic bonds High electrical conductivity High melting and boiling points

Question 28

What is meant by the term, Periodicity? (1)

Answer 28

The repeating trends in physical and chemical properties (1)

Question 29

Answer 29

D

Question 30

what is the colour of aqueous bromine?

Answer 30

Pale orange/brown

Question 31

Answer 31

B

Question 32

What is Disproportionation? (1)

Answer 32

The (simultaneous) oxidation and reduction of the same element (in the same redox reaction) (1)

Question 33

How does nuclear charge affect ionisation energy?

Answer 33

More protons creates a greater attraction between the nucleus and the outer electrons. therefore higher ionisation energy

Question 34

What is the name for the vertical columns of the periodic table?

Answer 34

Groups

Question 35

what block are group 2 metals found in and why?

Answer 35

s block, as the highest energy/ outer electron is found within the s sub-shell / orbital

Question 36

Who created the modern periodic table?

Answer 36

Dmitri Mendeleev

Question 37

Define first ionisation energy

Answer 37

The energy required to remove one electron from each atom in one mole of gaseous atoms of an element to form one mole of gaseous 1+ ions.

Question 38

what block are group 7 elements found in and why?

Answer 38

p block, as the highest energy/ outer electron is found within the p sub-shell / orbital

Question 39

What predictions can be made from a graph of successive ionisation energies?

Answer 39

The number of electrons in the outer shell, the group of the element in the periodic table and thus the identity of the element.

Question 40

How are elements arranged in the Periodic table? (2)

Answer 40

Elements are arranged by: – Increasing atomic (proton) number (1) – In groups with similar chemical properties (1)

Question 41

Define metallic bond

Answer 41

Strong electrostatic attraction between the cations and the delocalised electrons.

Question 42

Define Second Ionisation Energy.

Answer 42

The energy required to remove one electron from each 1+ ion in one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions

Question 43

Why do successive ionisation energies increase?

Answer 43

There are less electrons so the nuclear attraction on the remaining electrons will be greater.

Question 44

Explain the general trend of first ionisation energy across a period

Answer 44

``` Nuclear charge increases, Same shell: similar shielding, Nuclear attraction increases, Atomic radius decreases, First ionisation energy increases. ```

Question 46

Answer 46

C

Question 47

In period 3, why does silicon have the highest melting point?

Answer 47

Forms a giant covalent lattice, where each atom is covalently bonded to four others. Strong covalent bonds.

Question 48

Why do simple covalent molecules have low melting / boiling points?

Answer 48

Weak induced dipole-dipole forces between molecules are easy to break.

Question 49

what is meant by thermal decomposition?

Answer 49

using heat energy to break bonds and break the substance down

Question 50

what is the colour of aqueous iodine?

Answer 50

Pale brown

Question 51

Why does the melting point and boiling point increase across the metals of a period?

Answer 51

Number of delocalised electrons per atom and charge on cation increase, so stronger electrostatic attraction. Stronger metallic bonds.

Question 52

what is produced when CaO is added to water?

Answer 52

Calcium hydroxide

Question 53

Answer 53

A

Question 54

Why does ionisation energy decrease going down a group?

Answer 54

More electrons shells so the outer electrons are further away and there is a greater shielding effect.

Question 55

What is metallic bonding?

Answer 55

Each atom donates an outer shell electron, which becomes delocalised. This creates cations.

Question 56

Explain the trend of atomic radii across a period

Answer 56

Nuclear charge increases, Nuclear attraction increases, Atomic radius decreases across a period.

Question 57

What is the periodic trend in electron configuration?

Answer 57

The sub shells of n energy level fill up.

Question 58

Define second ionisation energy

Answer 58

The energy required to remove one electron from each ion in one mole of gaseous 1+ ions of an element to form one mole of gaseous 2+ ions.