Atomic Structure And The Periodic Table

Question 1

Equation for relative atomic mass

Answer 1

Sum of (isotope abundance X isotope mass)/ sum of abundance of all isotopes

Question 2

When is filtration used

Answer 2

Separate insoluble solids from liquids

Question 3

When is crystallisation and evaporation used

Answer 3

Separating soluble solids from liquids

Question 4

Simply describe the process of crystallisation

Answer 4

Heat solution gently until some of the solvent has evaporated then remove from heat bath. Solid crystals will then begin to form in the left over solution . Finally you have to filter it out

Question 5

Simply describe the process of evaporation to separate soluble solids from liquids

Answer 5

Heat solution until there is only crystals left

Question 6

Describe the process of distillation

Answer 6

1. Heat up the solution in the flask with a Bunsen burner until it evaporates
2. Gas will go down the the condenser.
3. Cold water jacket will cause the gas to condense
4. Liquid rolls back into the beaker

Question 7

When is simple distillation used

Answer 7

Separating out a liquid from a solution
(Separating pure water from sea water)

Question 8

How is evaporation used to separate soluble solids from liquids

Answer 8

1. Heat up solution until the solvent starts evaporating
2. Remaining solution becomes more concentrated
3. Crystals begin to form,

Question 9

Describe the process of fractional distillation

Answer 9

1.Heat is applied and the liquid with the lowest boiling point evaporates and condenses into a beaker
2. If other liquids evaporate by chance, they condense back into the flask because of the glass rods being a lower temperature than the boiling points.
3. The temperature is altered to repeat the process for the second liquid

Question 10

Why did Mendeleev Leave gaps in the periodic table

Answer 10

He predicted that there were elements with similar properties yet to be discovered

Question 11

Properties of metals

Answer 11

Very strong ( metallic bonding)
Malleable ( can be shaped or extend without snapping)
Conductors
High melting and boiling point
Sonorous ( produces sound when hit)

Question 12

Why do group 1 metals get more reactive as you go down the group

Answer 12

Electrons in the last shell are further away from nucleus meaning the attraction is weakened and electrons are easily lost making it more reactive.

Question 13

What happens as you go down group 1

Answer 13

Melting and boiling points decrease
Reactivity increases

Question 14

What happens as you go down group 7 (halogens)

Answer 14

Melting and boiling point increases
Reactivity decreasws

Question 15

Why does reactivity decrease as you go down group 7 (halogens)

Answer 15

Last shell gets further and further from the nucleus meaning the attractive force needed to pull in extra electrons is no longer there making it less reactive. ( group 7 elements are diatomic)