Chemistry Paper 1

Which subatomic particle was discovered first?

electron

Who discovered the electron?

JJ Thomson

Which subatomic particle was discovered last?

Neutron

Who discovered the neutron?

James Chadwick

Who discovered the proton?

Ernest Rutherford

Who discovered the nuclear atom model?

Niels Bohr

What are the group 1 elements called?

Alkali metals

What are the properties of alkali metals?

Weak, low density, low melting point

Describe the trend in reactivity for alkali metals

Reactivity increases as you go down the group

Describe the trend in melting/boiling point for alkali metals

Melting/boiling points decrease as you go down the group

What do ionic compounds formed by alkali metals normally look like?

White, soluble solids

Alkali metal + water ->

metal hydroxide + hydrogen gas

How do alkali metals react with water?

Vigorously

Alkali metal + oxygen ->

metal oxides

What are group 7 elements called?

halogens

What does fluorine look like at room temperature?

Poisonous yellow gas

What does chlorine look like at room temperature?

Poisonous green gas

What does bromine look like at room temperature?

Poisonous yellow/brown liquid

What does iodine look like at room temperature?

Grey solid (purple fumes)

Describe the trend in reactivity in halogens

Reactivity decreases as you go down the group

Describe the trend in melting/boiling points in halogens

Melting/boiling points increase down the groups

Why does the reactivity of halogens decrease down the group?

Greater distance between outer shell and nucleus means a weaker force of attraction, making it harder to pull in an electron for a full shell and then reactions

What are group 0 elements called?

Noble Gases

Describe the trend in melting/boiling points in noble gases

Boiling points increase as you go down the group

If an atom has 6 protons and 5 electrons, what charge will it have overall?

+1

True or false? Something counts as a 'molecule' when it's made from 2 or more atoms, and those atoms are held together by chemical bonds.

True

The atoms of elements in the same group have the same number of:

electrons in the outer shell

What is the best method to obtain a sample of salt from a salt solution?

evaporation

Do the melting and boiling points of the halogens increase or decrease as you go down the group?

increase

Define mixture

Two or more substances that are not chemically bonded

Oxygen molecules (O2) consist of two oxygen atoms. Is an oxygen molecule a compound?

No

Alkali metals react with water. Which two products are formed?

Hydrogen and metal hydroxide

Is an oxygen molecule a compound?

No

Name some properties of transition metals

Shiny, hard, good conductors, form colourful compounds, high melting/boiling points, form ions with different charges

Define molecule

A group of atoms bonded together

Define compound

Two or more different elements bonded together

What are some properties of transition metals?

dense, strong, shiny, good catalysts, coloured compounds

Describe the trend in boiling point as you go down group 1

Boiling point decreases

Describe the trend in boiling point as you go down group 7

Boiling point increases

Describe the trend in reactivity as you go down group 1

Reactivity increases

Describe the trend in reactivity as you go down group 7

Reactivity decreases

Describe fluorine

A very reactive, poisonous yellow gas

Describe chlorine

A fairly reactive, poisonous dense green gas

Describe bromine

A dense, poisonous, red-brown volatile liquid

Describe iodine

A dark grey solid or a purple vapour

Describe the properties of noble gases

Inert, colourless, non-flammable

Describe the trend of boiling points as you go down the Nobel Gases

Boiling point increases

Why did Mendeleev's periodic table become more widely accepted?

The gaps he left were filled as elements were discovered that had properties that matched Mendeleev's predictions

What is the modern name for atomic weight?

Relative atomic mass

Why is it not correct to say that the boiling point of a single molecule is a certain temperature?

Boiling point is a bulk property

Alkali metal + chlorine ->

metal chloride

Alkali metal and chlorine observations

flame, white solid formed

Alkali metal and water observations

bubbles from gas, flame for more reactive elements, metal disappears or floats on surface

Alkali metal and oxygen observations

burns with bright flame, white solid formed

What colour would universal indicator turn after reacting water and lithium and why?

Purple as lithium hydroxide is alkaline

Define metallic bonding.

the electrostatic force of attraction between the positive metal ions and the delocalised electrons

Describe the configuration of a metallic bond.

Lattice of positive ions surrounded by delocalised electrons.

Why are metals good conductors?

Delocalised/free electrons to carry a charge.

What do ionic bonds bond

Metals and non metals

What should all ionic charges in a compound sum to?

0.

Describe the structure of an ionic compound.

Giant lattice of alternating positive and negative ions

What has high melting and boiling points

Ionic compounds and metals.

When can an ionic compound conduct electricity

When dissolved in water (solution) or melted (molten)

Hydroxide ion

OH (1-)

Sulphate ion:

SO4 (2-.)

Carbonate ion

CO3 (2-).

Nitrate ion

NO3 (-)

Ammonium ion:

NH4 (+)

What bonds covalently

Non metals.

Define ionic bond.

The electrostatic force of attraction between oppositely charged ions.

Define covalent bond

The electrostatic force of attraction between a shared pair of electrons

What boiling points do simple covalent structures have and why?

low because of weak intermolecular forces

Can covalent structures conduct electricity

No

Define giant covalent structure

A large lattice consisting of repeating units of atoms

How many carbon atoms are bonded to each other in Diamond?

4.

How many carbon atoms are bonded to each other in a graphene layer

3 leaving one delocalised electron

Why can graphite conduct electricity

It has one delocalised electron to carry a charge around the structure.

What size are nanoparticles

1-100nm.

1 nm in m

10^-9 m

What size are coarse particles

2500 nm - 10 000 nm

What are coarse particles also known as?

Dust

State symbol of an aqueous substance.

(aq)

How is graphene structured?

3 carbon atoms in hexagonal rings.

why does graphene have a high melting/boiling point?

Strong covalent bonds that are hard to break.

How many atoms thick is graphene?

1.

Graphene could be useful in...

electronics.

What makes fullerenes unique to other carbon allotropes

They are hollow inside.

What is the formula for buckminsterfullerene?

C60.

Name some uses of buckminsterfullerene

Drug delivery

Lubricant in machine to reduce friction

Chemical catalysts.

What fullerenes are shaped into long cylinders

Carbon nanotubes.

What has a high length to diameter ratio?

Carbon nanotubes.

What is a property of carbon nanotubes that helps in engineering

High tensile strength.

Can carbon nanotubes conduct electricity

Yes as they have delocalised electrons.

Name one use of carbon nanotubes.

Reinforcements due to high tensile strength

How is a polymer made?

By joining together thousands of small identical molecules (monomers).

Are all covalent bonds in polymers strong?

Yes, very

What three things does the "repeating unit" show?

A single covalent bond,

Covalent bonds on either side have to extend out of brackets

Lower case n outside brackets to represent the number of repetitions

What forces are between polymer molecules

relatively strong intermolecular forces of attraction

Do polymers have a high or low melting/boiling point

High

What state are most polymers at room temperature.

Solid.