AQA GCSE Chemistry Paper 1 - Includes triple science content

use flashcards to test ur memory, then if u get something wrong, look back at the topic and watch some videos on freesciencelessons on youtube, then try exam questions from physicsandmathstutor

Topic 1 - Atomic Structure and the Periodic Table

1.1 - Atoms

1.2 - Elements, Isotopes & Relative Atomic Mass

1.3 - Compounds, Molecules & Mixtures

1.4 - Balancing Chemical Equations

1.5 - Filtration & Crystalisation

1.6 - Distillation

1.7 - The History of The Atom

1.8 - Electronic Structure

1.9 - Development of the Periodic Table

1.10 - Metals & Non-Metals

1.11 - Group 1 (Alkali Metals)

1.12 - Group 7 & Group 0 (Halogens & Noble Gases

1.1- atoms

1.2- elements, isotopes, relative atomic mass

1.3- compounds, molecules, mixtures

1.4- balancing equations

1.5- filtration and crystallisation

1.6- distillation

1.7- history of the atom

1.8- electronic structure

1.9- development of the periodic table

What is the charge of a proton?

+1

What is the charge of a neutron?

0

What is the charge of an electron?

-1

What is the relative mass of a proton?

1

What is the relative mass of a neutron?

1

What is the relative mass of an electron?

Very small - 1/1840

What are compounds?

Substances containing two or more different elements that are chemically bonded together

What are mixtures?

Substances containing two or more different elements that are not chemically bonded together

What pattern is formed from carrying out paper chromatography?

Chromatogram

Which method of separation is useful to separate an insoluble solid from a liquid?

Filtration

Which method of separation is useful to separate a soluble solid from a liquid?

Evaporation or Crystallisation

Which method of distillation separates liquids with similar boiling points?

Fractional distillation

What is the plum pudding model, and who discovered was wrong?

JJ Thomson devised that the atom was a ball of positive charge with negative electrons embedded throughout. Ernest Rutherford discovered that the plum pudding model was wrong

Who devised an experiment that proved the existence of the neutron?

James Chadwick

Why did Mendeleev leave gaps in his Table of Elements?

To ensure that elements with similar properties stayed in the same groups. The gaps indicated the existence of undiscovered elements and allowed Mendeleev to predict what their properties might be

How are the group number and the number of electrons in the outer shell of an element related?

The group number tells you how many electrons are in the outer shell of an element. E.g. sodium is in Group 1 therefore it has 1 electron in its outer shell

What kind of ions do metals form?

Positive- they lose electrons

Where are the non-metals on the periodic table?

On the right hand side

Give three properties which are specific to transition metals (Triple only)

1. They can form more than one ion e.g copper forms Cu+ and Cu2+

2. They are often coloured, therefore compounds which contain them are colourful e.g. potassium chromate is yellow

3. They often make good catalysts e.g. nickel based catalysts are used in the hydrogenation of alkenes

What trends occur as you go down Group 1?

1. Increased reactivity - the outer electron is more easily lost as the attraction between the nucleus and the electron decreases because the electron is further away from the nucleus

2. Lower melting and boiling points

3. Higher relative atomic mass

What are the products of the reaction between a Group 1 metal and water

Hydrogen gas and a metal hydroxide

E.g. sodium (s) + water (l) --> sodium hydroxide (aq) + hydrogen (g)

What's the difference between the hardness of Group 1 and transition metals?

Transition metals are harder, denser and stronger than Group 1 metals

What's the difference between the reactivity of Group 1 and transition metals? (Triple only)

Group 1 metals are much more reactive than transition metals

What's the difference between the melting points of Group 1 and transition metals? (Triple only)

Transition metals have higher melting points than Group 1 metals

What trends occur as you go down Group 7?

1. They become less reactive - it's harder to gain an extra electron because the outer shell's further from the nucleus so the force of attraction between the nucleus and the outer electron is weaker, so it is harder to attract an electron

2. They have higher melting and boiling points

3. They have higher relative atomic masses

What is the charge of the ions that halogens form when they react with metals?

They form negative ions by gaining electrons

What is the trend in boiling point as you go down Group 0?

The boiling points increase

What subatomic particles does the nucleus contain?

protons and neutrons

What is relative atomic mass?

The mass number which refers to the element as a whole

How are positive ions formed?

A metal atom loses electrons

How are negative ions formed?

A non-metal gains electrons

What is air a mixture of?

Gases, mainly nitrogen, oxygen, carbon dioxide and argon

What is crude oil a mixture of?

Different length hydrocarbon molecules

How can you separate substances in a mixture?

Chromatography

What is simple distillation used for?

Separating out a liquid from a solution

E.g. separating pure water from seawater

How were elements arranged in the early 1800s?

By their physical and chemical properties and their relative atomic mass

How are columns arranged?

Elements with similar properties

What are the three similar basic properties of metals?

1. They're strong but are malleable

2. They're great at conducting heat and electricity

3. They have high boiling and melting points

What is the product of the reaction of a Group 1 metal with a halogen?

A metal halide salt

E.g. sodium + chlorine --> sodium chloride

What is the product of the reaction of a Group 1 metal with oxygen?

A metal oxide, depending on the Group 1 metal

-Lithium + oxygen --> lithium oxide

-Sodium + oxygen --> sodium oxide + sodium peroxide

-Potassium + oxygen --> potassium peroxide + potassium superoxide

What are halogens?

Non-metals in Group 7 with coloured vapours

What colour is fluorine?

A very reactive, poisonous yellow gas

What colour is chlorine?

A fairly reactive, poisonous dense green gas

What colour is bromine?

A dense, poisonous red-brown volatile liquid

What colour is iodine?

A dark grey crystalline solid or a purple vapour

What do halogens exist as?

diatomic molecules (pairs of atoms)

What do halogens form?

1. Molecular compounds - halogens share electrons via covalent bonding with other non-metals too achieves a full outer shell

2. Ionic compounds with metals - they form 1- ions called halides

What do noble gases exist as?

Monatomic gases - single atoms not bonded to each other

What are the noble gases at room temperature?

Colourless gases

Are the noble gases flammable?

No - they're non-flammable

Why does the boiling point of noble gases increase as you move down the group?

There's an increase in the number of electrons in each atom leading to greater intermolecular forces between them which require lots of energy to overcome

What is the first step in paper chromatography?

Draw a pencil line near the bottom of a sheet of filter paper

What is the purpose of adding a spot of ink to the pencil line in paper chromatography?

To allow the ink to be carried by the solvent up the paper

Why is it important to ensure the ink is not touching the solvent in paper chromatography?

To prevent the ink from dissolving prematurely

What happens when different dyes in the ink move up the paper at different rates in paper chromatography?

The dyes separate out and form spots in different places

What occurs if any dyes in the ink are insoluble in the solvent used in paper chromatography?

They will stay on the baseline

What should be done when the solvent has nearly reached the top of the paper in paper chromatography?

Take the paper out of the beaker and leave it to dry

Simple Distillation - Method

1. The solution is heated. The part of the solution that has the lowest boiling point evaporates first

2. The vapour is then cooled, condensed & is collected

3. The rest of the solution is left behind in the flask

What is the problem with simple distillation?

You can only use it to separate things with very different boiling points - if the temperature goes higher than the boiling point of the substance with the highest boiling point, they will mix again

Fractional Distillation - Setup

1. Put your mixture in a flask & stick a fractionating column on top. Then you heat it

Fractional Distillation - Boiling Points

2. The different liquids will all have different boiling points - they'll evaporate at different temperatures

Fractional Distillation - Evaporation Order

3. The liquid with the lowest boiling point evaporates first. When the temperature on the thermometer matches the boiling point of this liquid, it will reach the top of the column

Fractional Distillation - Condensation

4. Liquids with higher boiling points might also start to evaporate, but the column is cooler towards the top, therefore they will only get part of the way up before condensing & running back down towards the flask

Fractional Distillation - Collecting Fractions

5. When the first liquid has been collected, you raise the temperature until the next one reaches the top

Radius of an atom

0.1 nanometers

Radius of a nucleus

1/10,000 of the radius of an atom

What type of ion do elements from Group 1 form?

Positive ions

What type of ion do elements from Group 7 form?

Negative ions

Topic 2 - Bonding, Structure and Properties of Matter

2.1 - Formation of Ions

2.2 - Ionic Bonding

2.3 - Ionic Compounds

2.4 - Molecular & Empirical Formulas

2.5 - Covalent Bonding

2.6 - Types of Covalent Structures

2.7 - Diamond & Graphite

2.8 - Graphene & Fullerenes

2.9 - Metallic Bonding

2.10 - States of Matter

2.11 - Nanoparticles (Triple only)

Describe how an ionic bond forms

When a metal and a non-metal react together, this causes the atoms to transfer electrons. The metal loses its electrons on its outer shell to form a positively charged ion. These electrons are gained by the non-metal to complete its outer shell, forming a negative ion.

Describe the structure of a crystal of sodium chloride

a giant ionic lattice. The positive sodium and negative chlorine ions form a closely packed regular arrangement and there are very strong electrostatic forces of attraction between the oppositely charged ions in all directions, and lots of energy is required to overcome them.

List the 4 main properties of ionic compounds

1. High melting and boiling points - many strong electrostatic forces between the ions

2. They can't conduct electricity when they're solid - the ions are held in a fixed arrangement therefore they can't carry charge.

3. They can conduct electricity when they're liquids because the ions are free to move and carry charge .

4. They dissolve easily in water - they are free to move in the solution and can carry charge

Describe how covalent bonds form

When two non-metals bond together, they share electrons to make covalent bonds. The positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces - this makes covalent bonds very strong.

Explain why simple molecular compounds typically have low melting and boiling points

The small atomic radii and the weak intermolecular forces between the compounds are very weak, therefore it takes only a small amount of energy to break them apart.

Describe the structure of a polymer

Polymers are long chains of repeating units joined together to make a long molecule. Between the atoms are strong covalent bonds.

Give three examples of giant covalent substances

-Diamond

-Graphite

-Silicon Dioxide

Explain why graphite can conduct electricity

It contains 3 covalent bonds and one extra delocalised electron which is free to move and can carry electrical charge

What is metallic bonding?

The electrons in the outer shell of a metal atom are delocalised. There are strong forces of electrostatic attraction between the positive metal ions and the negative electrons. These forces of attraction hold the atoms together in a regular structure.

List three properties of metals and explain how metallic bonding causes each property

1)Solid at room temperature - they have very high melting and boiling points because a lot of energy is needed to break the strong electrostatic forces of attraction between the metal atoms and delocalised electrons.

2)Good conductors of heat and electricity - the delocalised electrons can carry electrical current and thermal energy through the structure.

3)Malleable - the layers of metal atoms can slide over each other

Explain why alloys are harder than pure metals

The different sized atoms distort the layers, which makes it more difficult for them to slide over each other.