Periodic table

Question 1

Another name for Group One elements

Answer 1

alkaline metals

Question 2

Why does the reactivity increase as you go down group one?

Answer 2

As you go down group one the atoms get bigger so the outer electron will get further away from the nucleus. This means that the attraction from the nucleus becomes less, so the electron becomes more easily lost and so the metals become more reactive towards the bottom of group 1.

⬇ group 1
atom gets bigger
outer electron = further away from nucleus
attraction nucleus = less : electron = more easily lost : metals = more reactive ⬇ group 1

Question 3

Structure of reaction when Group One metal (Li) reacts with water

Answer 3

2 Li(s) + 2 H2O → 2 LiOH (aq PH – 13/14 Alkaline) + H2(g)

Question 4

Why are Group One metals kept in oil?

Answer 4

to protect them from reacting with the oxygen in the air

Question 5

Description of Group One reaction with water

Answer 5

• Fizzing
• Moving
• Spitting
• Floating
• Coloured flame

Question 6

What do you see when a fresh piece of a Group One metal is cut?

Answer 6

shiny as a metal

Question 7

physical properties of Group One metals:

Answer 7

• Hardness- soft and can be cut by knife
• Low melting and boiling point
• softness increases as you go down the group

Question 8

Colour + state of chlorine

Answer 8

Pale green, yellow gas

Question 9

colour + state of bromine

Answer 9

dark orange liquid

Question 10

colour + state of iodine

Answer 10

dark grey solid

Question 11

Test for chlorine

Answer 11

if chlorine gas is present then damp blue litmus paper should be turned red then bleached white

Question 12

Why does the reactivity increase as you go up group 7?

Answer 12

As you go down group 7 the atoms get bigger so the outer electron will get further away from the nucleus. This means that the attraction from the nucleus becomes less, so the electron becomes harder to gain and so the metals become more reactive towards the top of group 7.

Question 13

Displacement reactions involving halogens

Answer 13

in these reactions are more reactive halogen will displace the less reactive halogen from the compound
eg chlorine + sodium bromide -> sodium chloride + bromine

Question 14

Physical properties of the halogens

Answer 14

• exist as diatomic molecules
• melting and boiling point increases as you go down the group because intermolecular forces get stronger due to more points of contact.

Question 15

why are the noble gases unreactive

Answer 15

They have a full outer shell of electrons making them not want any electrons making them unreactive.

Question 16

Helium uses

Answer 16

• Used it airships as it’s less dense than air
• Used in oxygen tubes for deep sea divers
• used in neon signs

Question 17

neon uses

Answer 17

used in neon signs- when an electric current is passed through it – it glows

Question 18

Argon uses

Answer 18

-used and light bulbs to protect the filament from reacting with oxygen and nitrogen in the air

-used in neon lights

Question 19

Krypton and xenon uses

Answer 19

used in lasers

Question 20

Physical properties of a transition metal:

Answer 20

• Malleable, ductile, conducts heat and electricity well
• Far less reactive than main block metals
• Can form more than one type of ion eg. Cu 2+ & Cu 3+
• forms coloured compounds

Question 21

Mendeleev’s periodic table

Answer 21

Arranged the 50 or so known elements at the time in order of mass so that they formed columns of elements that had similar properties

He swapped some elements around so that they were not in order of mass but their properties fitted with the other elements in the column

He used his table to predict the existence and properties of yet undiscovered elements (eg germanium)

When these elements were discovered, scientists became convinced that Mendeleev’s table was a very important discovery.

Question 22

The Modern Periodic Table

Answer 22

Is different to Mendeleev’s as atomic number (number of protons in an atom) is used to order the elements not atomic mass. This gives a perfect pattern and no elements have to be ‘swapped’ around.

It contains 118 elements