Topic 1 - Atomic Structure And The Periodic Table

Question 1

What is a compound?

Answer 1

When an atom is chemically combined with another atom to make a compound

Question 2

What are the four key features of a chemical reaction?

Answer 2

• compounds are broken up or formed
• at least one new substance is formed
• there is a measurable energy change
• no atoms are created or destroyed

Question 3

What are mixtures?

Answer 3

2+ substances that haven’t been combined chemically and can be separated

Question 4

Do the chemical properties change in mixtures?

Answer 4

No

Question 5

What does chromatography separate?

Answer 5

Solutions with a number of different solutes (solids) in the solvent (liquid)

Question 6

What does filtration separate?

Answer 6

Mixtures that contain insoluble solids and liquids

Question 7

What does crystallisation separate?

Answer 7

Solutions into their separate parts (dissolved solids and liquids)

Question 8

What does fractional distillation separate?

Answer 8

Lots of liquids with different boiling points

Question 9

What does simple distillation separate?

Answer 9

Two liquids with different boiling points

Question 10

How does simple distillation work?

Answer 10

1) The mixture is heated until the liquid with the lower boiling point starts to boil
2) the vapour released passes through a condenser, where the gas cools back into a liquid

Question 11

Why is a thermometer used in simple distillation?

Answer 11

To make sure the highest boiling point isn’t exceeded otherwise both liquids would boil and the process would not separate them

Question 12

What did John Dalton describe atoms as?

Answer 12

Solid spheres

Question 13

What did JJ Thompson discover?

Answer 13

Electrons and came up with the ‘plum pudding model’ which shows atoms as a ball of positive charge with electrons stuck in it

Question 14

What experiment did Ernest Rutherford do?

Answer 14

The alpha particle scattering experiment - he fired positively charged alpha particles at a thin sheet of gold

Question 15

What conclusion did Ernest Rutherford reach?

Answer 15

The mass of an atom was concentrated in the centre and has positively charged protons

Question 16

What atomic model did Rutherford come up with?

Answer 16

The nuclear model

Question 17

What did Bohr discover?

Answer 17

Electrons orbit the nucleus at fixed distances

Question 18

Who discovered neutrons?

Answer 18

James Chadwick

Question 19

What is an element’s atomic number?

Answer 19

How many protons it has

Question 20

What is an element’s mass number?

Answer 20

The total number of protons and neutrons

Question 21

What are isotopes?

Answer 21

Atoms of the same element with the same number of protons but a different number of neutrons

Question 22

What is a relative atomic mass?

Answer 22

The average mass of all of the isotopes of an element

Question 23

What are elements on the periodic table organised by?

Answer 23

In order of their atomic number (how many protons they have). Every time you move an element to the right, the proton number increases by 1

Question 24

Why do elements in the same column/group react in similar ways?

Answer 24

They have the same number of electrons on their outer shell

Question 25

How did John Newlands organise the periodic table?

Answer 25

It was ordered by the mass of an element but the table was incomplete and some elements were placed in inappropriate groups

Question 26

What did Mendeleev do to the periodic table?

Answer 26

He recognised that there may be many undiscovered elements so added gaps to account for them. He also predicted the properties and masses of the undiscovered elements. - he put elements in order of relative atomic mass

Question 27

Where are metals found on the periodic table?

Answer 27

The left because they have few electrons on their outer shell

Question 28

Properties of metals:

Answer 28

High melting and boiling point Solid @ room temperature Good conductors of heat and electricity

Question 29

Where are non-metals found on the periodic table?

Answer 29

The right hand side because they have many electrons on their outer shell

Question 30

Properties of non-metals:

Answer 30

Low melting and boiling points Normally found as gases Generally do not conduct heat or electricity

Question 31

Where are noble gases found?

Answer 31

In group 0

Question 32

Properties of noble gases:

Answer 32

Unreactive because they have a full outer shell already Can be used in light bulbs as don’t react with the hot metal filament Low boiling point Low density

Question 33

What does it mean by ‘noble gases are monatomic’

Answer 33

Noble gases exist as single atoms instead of forming molecules because they are unreactive

Question 34

What happens to the boiling point of noble gases as you go down the periodic table?

Answer 34

The boiling point increases Due to the number of electrons increasing meaning there are greater intermolecular forces

Question 35

What happens to the density of noble gases as you go down the group?

Answer 35

It increases because of the increasing relative atomic mass. Low density makes them useful for balloons

Question 36

Where are halogens found?

Answer 36

Group 7

Question 37

Properties of halogens:

Answer 37

- very reactive because they easily accept an electron into the outer shell - form negative ions - diatomic molecules

Question 38

What happens to the reactivity of halogens as you move down the periodic table?

Answer 38

It decreases because the distance between the outer electron shell and the nucleus increases so the attraction between the nucleus and the electron (to be gained from another element) decreases

Question 39

What can happen to less reactive halogens?

Answer 39

They can be displaced by more reactive halogens from compounds

Question 40

What are the elements found in group one referred to as?

Answer 40

Alkali metals

Question 41

What happens to the reactivity of alkali metals as you move down the periodic table?

Answer 41

It increases because the distance between the outer electron and the nucleus increases meaning there is a weaker force of attraction between them and it’s easier for an electron to be lost

Question 42

How do group one metals react with water?

Answer 42

The metal floats on the surface and melts to create a metal hydroxide. The energy released in fed reaction is enough to melt the metal

Question 43

How do group one metals react with chlorine?

Answer 43

A metal chloride is formed which dissolves in water to give a colourless solution

Question 44

How do group one metals react with oxygen?

Answer 44

The metal rapidly turns from silvery/shiny to dull as a metal oxide is produced

Question 45

Where are transition metals found?

Answer 45

In the middle of the periodic table

Question 46

Relative to the alkali metals what are the properties of transition metals:

Answer 46

- higher density - greater strength and hardness - lower reactivity - higher melting points - can be used as catalysts