Module 3 – Periodic Table & Energy

Question 1

What is a common name given to group 2 metals?

Answer 1

Alkaline earth metals

Question 2

What is the most reactive metal of group 2?

Answer 2

Barium

Question 3

List 3 physical properties of group 2 metals

Answer 3

1. High melting and boiling points 2. Low density metals 3. Form colourless (white) compounds

Question 4

The highest energy electrons of group 2 metals are in which subshell?

Answer 4

S subshell

Question 5

Does reactivity increase or decrease going down group 2? Why?

Answer 5

• Increases - Electrons are lost more easily because larger atomic radius and more shielding

Question 6

What happens to the first ionisation energy as you go down group 2? Why?

Answer 6

Decreases because: - Number of filled electron shells increases down the group, therefore increased shielding - Increased atomic radius therefore weaker force between outer electrons and nucleus - So less energy needed to remove an electron

Question 7

What type of reaction is the reaction between group 2 elements and oxygen?

Answer 7

Redox reaction

Question 8

Write an equation for the reaction of calcium and oxygen

Answer 8

2Ca (s) + O2 (g) -> 2CaO (s)

Question 9

What is the product when group 2 elements react with water?

Answer 9

Hydroxide and hydrogen gas

Question 10

Which group 2 element doesnt react with water?

Answer 10

Beryllium

Question 11

Which group 2 element reacts very slowly with water?

Answer 11

Magnesium

Question 12

What type of reaction is the reaction between group 2 metals and water?

Answer 12

Redox reaction

Question 13

Write an equation for the reaction of Barium and water

Answer 13

Ba (s) + 2H2O (l) -> Ba(OH)2 (aq) + H2 (g)

Question 14

What is oxidised and what is reduced in a reaction between a group 2 metal and water?

Answer 14

The metal is oxidised One hydrogen atom from each water is reduced

Question 15

What are the products when a group 2 element reacts with dilute acid?

Answer 15

Salt and hydrogen gas

Question 16

Write an equation for the reaction of calcium and hydrochloric acid?

Answer 16

Ca (s) + 2HCl (aq) -> CaCl2 (s) + H2 (g)

Question 17

What is formed when group 2 oxides react with water?

Answer 17

Metal hydroxide

Question 18

Write an equation for the reaction between a group 2 oxide (M) and water

Answer 18

MO (s) + H2O (l) -> M(OH)2 (aq)

Question 19

What group 2 metal oxide is insoluble in water?

Answer 19

Beryllium oxide

Question 20

What is the trend in hydroxide solubility down group 2?

Answer 20

• Increases down the group - Mg(OH)2 is slightly soluble - Ba(OH)2 creates a strong alkaline solution

Question 21

What is Ca(OH)2 used for? Write an equation related to one of its uses

Answer 21

Used to neutralise soil Ca(OH)2 (aq) + 2HCl (aq) -> 2H2O (l) + CaCl2 (aq)

Question 22

What is Mg(OH)2 used for?

Answer 22

An antacid to treat indegestion, heartburn, ect

Question 23

What is calcium carbonate used for?

Answer 23

Present in limestone and marble Used in building construction

Question 24

What is the drawback of using calcium carbonate in construction? Write a related equation

Answer 24

Group 2 carbonates react with acid CaCO3 (s) + 2HCl (aq) -> CaCl2 (aq) + H2O (l) + CO2 (g)

Question 25

How are the elements arranged in a periodic table?

Answer 25

They are arranged in the order of increasing atomic numbers

Question 26

What is a period on the periodic table?

Answer 26

The horizontal rows in the periodic table

Question 27

What is a group on a periodic table?

Answer 27

The vertical columns

Question 28

What is meant by periodicity?

Answer 28

The repeating trends in chemical and physical properties

Question 29

What change happens across each period?

Answer 29

Elements change from metals to non-metals

Question 30

How can the electron configuration be written in short?

Answer 30

The nobel gas before the element is used to abbreviate E.g. Li -> 1s22s1 ; Li -> [He] 2s1

Question 31

Define first ionisation energy

Answer 31

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

Question 32

Write an equation for the first ionisation energy of magnesium

Answer 32

Mg (g) -> Mg+ (g) + e-

Question 33

What are the factors that affect ionisation energy?

Answer 33

Atomic radius Nuclear charge Electron shielding or screening

Question 34

Explain the trend on this graph

Answer 34

First ionisation energy increases across period 3 because of: Increased nuclear charge Decreased atomic radius Same electron shielding So more energy is needed to remove the first electron Dips at Al because: Outer electron is in a 3p orbital 3p orbital is higher energy than 3s orbital Less energy is needed to remove the electron Dips at S because: One 3p orbital contains 2 electrons Repulsion occurs between the paired electrons Less energy is needed to remove an electron

Question 35

Why does first ionisation energy decrease between group 2 and 3?

Answer 35

In group 3 the outermost electrons are in p orbitals In group 2 the outermost electrons are in s orbitals Electrons in p orbitals are easier to remove

Question 36

Why does first ionisation energy decrease between group 5 to 6?

Answer 36

Group 5 electrons in p orbital are single electrons Group 6 electrons are spin paired, with some repulsion So group 6 electrons are easier to remove

Question 37

Does first ionisation increase or decrease between the end of one period and the start of the next? Why?

Answer 37

Decrease Atomic radius increases Electron shielding increases

Question 38

Does first ionisation increase or decrease down a group? Why?

Answer 38

Decrease Shielding increases so attraction is weaker Atomic radius increases Distance between the outer electrons and nucleus increases Attraction is weaker Increase in number of protons is outweighed by increase in distance and shielding

Question 39

What are the properties of giant metallic lattices? (4)

Answer 39

High melting and boiling point Good electrical conductors Malleability Ductility

Question 40

What is a ductile metal?

Answer 40

A metal which can be stretched E.g. can be made into wires

Question 41

What is a malleable metal?

Answer 41

The metal can be shaped into different forms

Question 42

Describe the structure, forces and bonding in every element across period 2

Answer 42

Li and Be -> giant metallic; strong attraction between positive ions and delocalised electrons; metallic bonding B and C -> giant covalent; strong forces between atoms; covalent N2, O2, F2 and Ne -> simple molecular; weak intermolecular forces between molecules; covalent bonding within molecules and intermolecular forces between molecules

Question 43

Describe the structure, forces and bonding in every element across period 3

Answer 43

Na, Mg, Al -> giant metallic; strong attraction between positive ions and delocalised electrons; metallic bonding Si -> giant covalent; strong forces between atoms; covalent P4, S8, Cl2, Ar -> simple molecular; weak intermolecular forces between molecules; covalent bonding within molecules and intermolecular forces between molecules