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Question 1

What is an element?

Answer 1

Made of one type of atom

Question 2

What is a compound?

Answer 2

Substance made of different types of atoms bonded together

Question 3

Differences between compounds and mixtures

Answer 3

Mixtures aren’t chemically combined

Question 4

What is filtration

Answer 4

Separate insoluble substances from a solution

Question 5

What is crystallisation

Answer 5

Evaporate water from solution to leave crystals

Question 6

What is fractional distillation

Answer 6

When liquids are separated because of their boiling points

Question 7

What did JJ Thompson discover

Answer 7

Electron

Question 8

What is an ion

Answer 8

Atom with different number of electrons

Question 9

What is an isotope

Answer 9

Different number of neutrons

Question 10

What is an atom?

Answer 10

The smallest part of an element

Question 11

What do the symbols in the periodic table represent?

Answer 11

Atoms

Question 12

What is a compound?

Answer 12

Different types of atoms bonded together

Question 13

What is the law of conservation of mass?

Answer 13

The total mass of products formed = mass of reactants

Question 14

What holds a compound together?

Answer 14

Chemical bonds

Question 15

Is hydrogen a metal or non metal?

Answer 15

Hydrogen is a metal. A metal must conduct heat and electricity, which solid hydrogen does. The properties of metals like malleability are just coincidence

Question 16

With open containers, why does it sometimes look like the law of conservation of mass is broken?

Answer 16

With gases, the carbon dioxide formed will escape or oxygen will enter. When gas escapes, the law is kept because oxygen will react with the metal to keep the weight the same

Question 17

What is an element determined by?

Answer 17

Number of protons

Question 18

When you change the number of neutrons, you get an

Answer 18

Isotope

Question 19

When you change the number of electrons, you get an

Answer 19

Ion

Question 20

How to separate elements in a compound

Answer 20

Chemical reaction

Question 21

What does filtration separate?

Answer 21

One solute that is soluble in a solvent and one that isn’t

Question 22

How does crystallisation work?

Answer 22

Filter the substances, then evaporate the liquid to leave the material

Question 23

When should heating be stopped during crystallisation?

Answer 23

When the solution is just forming crystals

Question 24

What are elements ordered by in p table?

Answer 24

Smaller number - atomic number

Question 25

How to calculate the relative atomic mass using isotopes

Answer 25

Multiply percentage by mass, add and the divide by 100

Question 26

What are the columns in the periodic table called?

Answer 26

Groups

Question 27

What does the symbol of an element show?

Answer 27

One atom of that element

Question 28

What do chemical equations show?

Answer 28

The reactants and the products

Question 29

What happens in a chemical reaction?

Answer 29

The atoms in the reactants get rearranged into the products

Question 30

What is an aqueous solution?

Answer 30

A substance that has been dissolved in water

Question 31

Process of filtration

Answer 31

Pour the mixture through a filter funnel

Question 32

Process of evaporation

Answer 32

Heat the solution with a Bunsen burner | Keep heating until all the liquid has gone and you are left with dry crystals

Question 33

Process of crystallisation

Answer 33

``` Gently heat the solution Once some of the liquid has evaporated, stop heating Leave the solution to cool Now more crystals will form Filter the crystals out and you're done ```

Question 34

Process of chromatography

Answer 34

Draw a pencil line on the paper Place blobs of your ink Place it in water so the ink isn't touching the liquid The solvent will move up the paper and carry the ink

Question 35

When to use simple distillation?

Answer 35

When you want to separate a liquid from a solution

Question 36

Process of simple distillation

Answer 36

The solution is heated to evaporate the part of it with the lowest boiling point first This vapour is cooled, condensed and collected

Question 37

When to use fractional distillation

Answer 37

When you have a mixture of liquids with similar boiling points

Question 38

Process or fractional distillation

Answer 38

You heat your mixture until it reaches the boiling point of the first liquid This liquid evaporates first It reaches the top of the column, runs down the tubs and is collected You repeat this with higher temperatures

Question 39

What did John Dalton suggest

Answer 39

Atoms were tiny, hard spheres

Question 40

Who discovered the electron?

Answer 40

J J Thompson

Question 41

Who discovered the nucleus and how?

Answer 41

Geiger and Marsden | Fired atoms at gold foil and some rebounded (they bounced off the electrons)

Question 42

Who discovered that electrons were in shells?

Answer 42

Niels Bohr

Question 43

Who found there were neutrons in the nucleus?

Answer 43

James Chadwick

Question 44

Charge of proton

Answer 44

1+

Question 45

Mass of proton

Answer 45

1+

Question 46

Charge of neutron

Answer 46

0

Question 47

Mass of neutron

Answer 47

1

Question 48

Charge of electron

Answer 48

-1

Question 49

Mass of electron

Answer 49

Very small

Question 50

What is the mass number?

Answer 50

The mass of the nucleus

Question 51

What is the atomic number?

Answer 51

The number of electrons or protons

Question 52

When an atom gains electrons what is the charge on the ion?

Answer 52

-

Question 53

When an atom loses electrons what is the charge on the ion

Answer 53

+

Question 54

Why will isotopes of the same element have the same chemical properties?

Answer 54

Their chemical properties depends on their electronic structure

Question 55

How to write the electronic structure

Answer 55

Number of electrons in first she'll, followed by second, third, etc Eg 2,8,4

Question 56

What determines how an element reacts

Answer 56

Electrons in outer shell

Question 57

What experiment did JJ Thomson do and how did this lead to him finding the electron?

Answer 57

He found that the mysterious particle was attracted to a positive charge, showing they must be negatively charged

Question 58

What was Bohr's experiment?

Answer 58

he noticed light was given out when electrons were heated - they were moving between energy levels

Question 59

What was Geiger and Marsden's experiment?

Answer 59

They fired alpha particles at gold foil. Due to the current model of the atom, which was the plum pudding one,they expected most of the particles to pass straight through. The positive alpha particles were deflected by the negative electrons however

Question 60

Why is it impossible to predict the mass of crystals that can be obtained during crystallisation?

Answer 60

Mixtures have no fixed composition