topic 1 - atomic structure + the periodic table

Question 1

what’s the radius of an atom?

Answer 1

around 0.1 nanometres ( 1 * 10^-10 m)

Question 2

what’s the nucleus of an atom?

Answer 2

in the middle of the atom, it contains protons and neutrons and so has a positive charge. almost the whole mass of the atom is concentrated in the nucleus. the radius of the nucleus is around 1/10000 of the radius of an atom

Question 3

what are electrons

Answer 3

negatively charged subatomic particle that orbit the nucleus in shells. they are tiny so have virtually no mass.

Question 4

what are protons

Answer 4

positively charged subatomic particles that are found in the nucleus. they have a relative mass of 1

Question 5

what are neutrons

Answer 5

neutrally charged subatomic particles that are found in the nucleus. they have a relative mass of 1

Question 6

what are elements

Answer 6

they consist of atoms with the same atomic number

Question 7

what are isotopes

Answer 7

different forms of the same element, which have the same number of protons but different numbers of neutrons

Question 8

what’s the formula for relative atomic mass of isotopes

Answer 8

relative atomic mass = sum of (isotope abundance*isotope mass number)/sum of abundances of all the isotopes

Question 9

what are compounds

Answer 9

substances formed from two or more elements, the atoms of each are in fixed proportions throughout the compound and they’re held together by chemical bonds

Question 10

What is a mixture

Answer 10

Multiple elements or compounds that are not chemically bonded together and so can easily be separated out

Question 11

What is chromotography used for

Answer 11

To separate different dyes in ink

Question 12

What is filtration used for

Answer 12

To separate insoluble solids from liquids

Question 13

What are two ways to separate soluble solids from solutions

Answer 13

• evaporation
• crystallisation

Question 14

How can you separate rock salt

Answer 14

1) grind it
2) put the mixture in water so the salt dissolves
3) filter out the sand
4) evaporate the water

Question 15

What is simple distillation used for

Answer 15

Separating out a liquid from a solution (e.g pure water from seawater)

Question 16

Describe simple distillation

Answer 16

The solution is heated and the part of the solution that has the lowest boiling point evaporates first. The vapour is then cooled and condenses, and is collected.

Question 17

What is the problem with simple distillation

Answer 17

It can only be used to separate things with very different boiling points

Question 18

What is fractional distillation used for

Answer 18

Separating a mixture of liquids that can have similar boiling points

Question 19

How does fractional distillation work

Answer 19

Heat the mixture under a fractioning column, the different liquids will have different boiling points and so evaporate and condense at different temperatures. Liquids with higher boiling points will condense quicker and so will not reach the top of the fractioning column. Lower boiling points will reach the top and drain out through the condenser. Then raise the temperature.

Question 20

Who came up with the plum pudding model

Answer 20

JJ thomson

Question 21

Who conducted the alpha particle scattering experiments

Answer 21

Rutherford

Question 22

What were the results of the alpha particle scattering experiments

Answer 22

Some particles were deflected more than expected, disproving the plum pudding model. Rutherford came up with a new idea of the atom - positive nucleus surrounded by a cloud of negative electrons

Question 23

What was the problem with Rutherfords model of the atom

Answer 23

The electrons would be attracted to the nucleus and the atom would collapse

Question 24

Who added that electrons orbited the nucleus in shells

Answer 24

Bohr

Question 25

Who discovered neutrons

Answer 25

James Chadwick

Question 26

Why did Menderleev leave gaps in the periodic table

Answer 26

So elements with similar properties stayed in the same groups

Question 27

What helped confirm Mendeleev’s periodic table

Answer 27

• the discovery of elements that fitted the patterns he predicted
• the discovery of isotopes

Question 28

What are the properties of metals

Answer 28

• strong and hard to break
• Good conductors of heat and electricity
• malleable
• high melting and boiling points

Question 29

What are the properties of non - metals

Answer 29

• dull looking
• more brittle
• don’t usually conduct electricity
• lower density than metals

Question 30

What are the properties of transition metals

Answer 30

• can form more than one ion
• often coloured
• Good catalyst
• less reactive and much harder than group 1 elements

Question 31

How do alkali metals react with water

Answer 31

Vigorously - producing hydrogen gas and metal hydroxides

Question 32

How do alkali metals react with chlorine

Answer 32

Vigorously- to produce metal chloride salts

Question 33

What does an alkali metal reacting with oxygen form

Answer 33

Metal oxides

Question 34

What’s a displacement reaction

Answer 34

A more reactive element displacing a less reactive one

Question 35

Why are group 0 metals unreactive

Answer 35

They have a full outer shell and exist as monatomic gases