Unit 4

Question 1

What is the periodic table

Answer 1

A list of all the elements, in order of increasing atomic number

Question 2

What are the columns called in the periodic table

Answer 2

Groups

Question 3

What are the rows in the periodic table called

Answer 3

Periods

Question 4

What does the group number tell you

Answer 4

How many electrons that are in the outer shell of the atoms

Question 5

What are Vallency electrons

Answer 5

The outer shell electrons

Question 6

Group 1

Answer 6

The alkali metals

Question 7

Group 2

Answer 7

Alkaline earth metals

Question 8

Group 7

Answer 8

The halogens

Question 9

Group 0

Answer 9

The noble gases

Question 10

Periods

Answer 10

The period number gives information about the number of electrons shells that are available in that period

Question 11

Hydrogen

Answer 11

Hydrogen sits alone in the table because it’s the only element with one electron shell

Question 12

Trends in the periodic table

Answer 12

The elements in each numbered group show trends in their properties. For example as you go down group 1, the elements become more reactive or as you go down group 7 elements become less reactive and so on

Question 13

Group 1-alkali metals
Physical properties
Chemical properties

Answer 13

Their physical properties:

1. Like all metals, they are good conductors of heat and electricity.
2. They are softer than most other metals.
3. they have low melting and boiling points, compared to most metals

Their chemical properties:

1. All alkali metals react vigourously with water, releasing hydrogen gas and forming hydroxides. The hydroxides give alkaline solutions.
2. They react with non-metals. With chlorine they react to make chlorides and with oxygen they make oxides.

They form ionic compounds in which the metal ion has a charge of positive one. The compounds are white solids, which dissolves in water to give a colourless solution.

Question 14

The trend in physical properties (group 1) 
As it goes down 
Softness increases 
Density increases 
Melting points decrease 
Boiling points decreases

Answer 14

Lithium
Sodium
Potassium
Rubidium 
Season

Question 15

Why did they have similar properties

Answer 15

Because atoms of the same number of Vallency electrons react in a similar way

Question 16

Why The further you go down the group reactivity increases

Answer 16

Because the atoms get larger down the group because they add electron shells

Question 17

Group 7-the halogens

Answer 17

I’m nonmetal group
From coloured gases
Are poisonous
Are brittle and crumbly in their solid form, and do not conduct electricity
Form diatomic molecules (means they exist as 2 atoms)

Question 18

Trends in their physical properties ( group 7)
As you go down : 
Size and mass of atom increases
Density increases 
Melting and boiling points increase

Answer 18

Chlorine
Bromine
Iodine

Question 19

Why does the reactivity increase as you go up group 7

Answer 19

Because the smaller the atom, the easier it is to attract the electron - so the more reactive an element will be

Question 20

Why are they so reactive (group 7)

Answer 20

Because their atoms are only one electron short of a full shell

Question 21

Group 0: the noble gases

Answer 21

A non-metal group
Contains colourless gasses, which occur naturally in air
Monatomic-they exist as single atoms
Unreactive because they have a full outer shell

Question 22

Trends in their physical properties (group 0)
As you go down 
Size and mass of atom increases 
Density of gas increases 
Boiling points increases

Answer 22

Helium 
Neon 
Argon 
Krypton
Xenon

Question 23

Uses of noble gases

Answer 23

Noble gases are unreactive, making them safe to use. They also grow when current is passed through them at low pressure.

Question 24

Use of helium (noble gases)

Answer 24

Used to fill balloons and airships, because it is much lighter than air and will not catch fire.

Question 25

Use of neon (noble gases)

Answer 25

Used in advertising signs. It glows red, but the colour can be changed by mixing it with other gases.

Question 26

What can argon be used for? (Noble gases)

Answer 26

Used as a filler in ordinary tungsten light bulbs (oxygen would make the tungsten filament burn away)

Used to protect metals that are being welded. It won’t react with the hot metals (unlike oxygen)

Question 27

What is krypton used for (noble gases)

Answer 27

Used in lasers. For example for eye surgery and in car headlamps

Question 28

What is xenon used for? (Noble gases)

Answer 28

Used in Lighthouse lamps, lights for hospitals operating theatres, and car headlamps.

Question 29

The physical properties of transition elements

Answer 29

Hard, tough and strong
High melting points (mercury is an exception)
Malleable and ductile
Good conductors of heat and electricity 
High density

Question 30

What are transition elements

Answer 30

The transition elements are the block of 30 elements in the middle of the periodic table. They are all metals.

Question 31

What are the chemical properties of transition elements

Answer 31

They are much less reactive than the metals of group 1
They show no clear trend in reactivity, unlike the metals of group 1.
Most transition metals form coloured compounds
Most can form ions with different charges (they have variable Vallency)
They can form more than one compound with another element
Most transition metals can form complex ions.

Question 32

Uses of transition metals

Answer 32

The hard strong transition metals are used in structure such as bridges, buildings, cars etc.
Many transition metals are used in making alloys
Transition metals are used as conductors of heat and electricity
Many transition metals and their compounds act as catalysts