Atomic Structure

Question 1

What is an Atom?

Answer 1

> The smallest particle of a chemical element that can exist.

Question 2

What is an elememt?

Answer 2

> A substance that is made from only one type of atom.

Question 3

What is a compound?

Answer 3

> Contains two or more elements chemically combined in fixed proprotions

Question 4

What is a Mixture

Answer 4

> They have different elements or compounds not chemically combined together.

Question 5

What is a molecule?

Answer 5

> Has any elements chemically joined.

Question 6

Explain Filtration?

Answer 6

> It separates an insoluble from a liquid
useful for separating sand from a liquid
It works because the filter paper has holes which are large enough to let small molecules and dissolved ions.

Question 7

Explain the method to carry out Filtration?

Answer 7

1)One beaker contains a mixtures of solids and liquids, other containing funnel with filter paper.
2)The solid and liquids is poured into the funnel paper.
3)The liquid drips through the filter paper but the solid particles are caught in the filter.

Question 8

Explain Crystallisation?

Answer 8

> It separates a soluble solid from a liquid
Produces crystals from a solution

Question 9

Explain the method to carry out Crystallisation?

Answer 9

1)A solution is places in an evaporating basin and heated within a Bunsen burner
2)Volume of solution decreases because the water has evaporated.
3)All water has evaporated, leaving solid crystals behind.

Question 10

Explain Simple Distillation?

Answer 10

> To separate a liquid from a dissolved solid
Useful for producing pure water from sea water.

Question 11

Explain the method to carry out Simple Distillation?

Answer 11

> Salty water is heated
The water vapour cools the condenser and drips into the beaker.
The water has condensed and now in the beaker, the salt stays behind

Question 12

What was the first discovery of electrons?

Answer 12

> John Dalton experiments led to the idea that atoms were very small sphere which can’t be divided.

Question 13

What did JJ Thomson Do?

Answer 13

> He discovered the ‘electrons’ and made the plum pudding model which suggests atoms were spheres of positive change with negative charged embedded in it.

Question 14

What did Rutherford Do?

Answer 14

> Alpha particle scattering experiment.

Question 15

What did the Nuclear Model prove?

Answer 15

> Mass of atoms were concentrated in a charged nucleus.
It proved electrons orbited a Nucleus.

Question 16

What happened after the Nuclear Model?

Answer 16

> Niels Bohr proposed electrons orbit nucleus at specific distances in fixed energy levels.
Later it was proposed that it was positive charge of nucleus which could be subdivided into particles of positive charge?

Question 17

What did James Chadwick?

Answer 17

> Provided evidence for the existence of neutrons

Question 18

What is Relative Atomic Mass?

Answer 18

> The weighted mean of mass of an element, taking into account all of the different isotopes and their relative abundance.

Question 19

What is the formula for Relative Atomic Mass?

Answer 19

                  100

Question 20

How are periodic tables arranged now compared to before?

Answer 20

> Early periodic table=atomic weight.
Now=atomic number

Question 21

Outline the history timeline of the Periodic Table

Answer 21

1)Law of Triad-arranged by similar reactivity
2)Law of Octaves-Realised every 8 was similar but failed
3)Mendeleev-Started with atomic weight, left gaps for the future to find.

Question 22

What is a ‘group’?

Answer 22

> Elements with similar chemical properties.

Question 23

What is a ‘period’?

Answer 23

> Each row in the table

Question 24

What are the properties of the Noble gases (Group 0)?

Answer 24

> Full Outer shell
Don’t do reactions
Don’t form molecules
Colourless gases
Low Bioling Point
Atomic mass increases down the group
Density increases
B.P. increases

Question 25

What are properties of Alkali Metals (Group 1)?

Answer 25

> Low Density
Soft
Shiny when cut
Metals
Always lose 1 electron
Very reactive
Reactivity increases as you go down

Question 26

What is the reaction with Alkali Metal + Oxygen?

Answer 26

> Room Temp: Colour change from shiny to white.
Hot: Burning vigorously farming white smoke.

Question 27

What is the reaction with Alkali Metal + Chlorine?

Answer 27

> Very vigorous, product a metal chloride= slat.
Dissolves easily to make colourless solutions.

Question 28

What is the reaction with Alkali Metal + Water?

Answer 28

> Very vigorous, fizzing, floats in water and dissolves solution is alkaline, metal blast releasing lilac flame.

Question 29

What are the properties of the Halogens (Group 7)?

Answer 29

> Non-Metals
Low M.P. and B.P.
B.P. and M.P. increases
They always gain

Question 30

What is the trend in reactivity in Group 7?

Answer 30

> The more you go down the less reactive
The closer the nucleus is, the easier to attract electrons
The more down you go electrons are further away from the nucleus, the harder it is to attract.
Harder to gain an electron=less reactivity.