C1 - Atomic Structure

Question 1

Atoms

Answer 1

the smallest part of an element that can exist. All substances are made up of them.

Question 2

Elements

Answer 2

substances that are made up of one type of atom.

Question 3

What are groups

Answer 3

elements in the periodic table arranged in columns with other elements with similar properties as them.

Question 4

Compound

Answer 4

substance consisting of two or more types of atom, joined together by chemical bonds.

Question 5

Law of conservation of mass

Answer 5

the total mass of the products formed is equal to the total mass of the reactants. Due to this we must balance equations.

Question 6

State symbols

Answer 6

solid (s), liquid(l), gas(g) and aqueous solutions/ substances which are dissolved in water (aq).

Question 7

Mixture

Answer 7

substance consisting of two or more types of atom, not joined together by chemical bonds.
They, unlike compounds,
- have no fixed composition and
- the elements can be separated easily without chemical reactions.

Question 8

Filtration

Answer 8

separating an insoluble substance from a soluble substance dissolved in a solvent, using a funnel and filter paper.

Question 9

Crystallisation

Answer 9

separating a soluble substance from a solvent, using an evaporating dish on a water bath to evaporate the solvent.

Question 10

Simple distillation

Answer 10

separating a solvent from a soluble substance without evaporating the solvent, using a condenser which condenses hot vapour of the solvent back into liquid in a receiving vessel.
The solute is left behind in the original flask.

Question 11

Miscible

Answer 11

liquids which dissolve in each other, mixing completely

Question 12

Fractional distillation

Answer 12

separating two miscible liquids, using a condenser for condensing the vapour of the liquid with the lower boiling point, then the same with the higher boiling point.

The separation is only possible because of the different boiling points of the liquids in the mixture.

Question 13

Chromatography

Answer 13

separating and identifying mixtures in a solution,
using a capillary tube to dot the solution on the bottom of the chromatography paper and placing paper in solvent for mixtures to soak upwards.
The more soluble a mixture is in solvent, the further it goes up the paper

Question 14

John Dalton’s contribution to the atom

Answer 14

put forward ideas that substances are made of atoms which are tiny, hard spheres.
Each element has its own mass, atoms rearrange themselves in reactions and cannot be split or divided.

Question 15

J.J. Thompson’s contribution to the atom

Answer 15

He created the plum pudding model which stated that negative electrons are embedded in a positive cloud, with not overall charge.

Proved existence of electron by applying high voltages to gases in low pressure.

Question 16

Rutherford’s contribution to the atom

Answer 16

he did the gold foil experiment where he discovered that the positive charge in an atom is concentrated on one nucleus because some alpha particles fired at gold foil were repelled back. Proved existence of the nucleus.

Question 17

Niels Bohr’s contribution to the atom

Answer 17

light given out when atoms heated has different specific amounts of energy because electrons ‘jump’ from a higher to lower electron shell when energy is emitted. Proved existence of the shells.

Question 18

Chadwick’s contribution to the atom

Answer 18

carried out an experiment to prove existence of neutrons in nucleus.

Question 19

Proton

Answer 19

relative atomic mass = 1

charge = +1

Question 20

Neutron

Answer 20

relative atomic mass = 1, charge = 0

Question 21

Electron

Answer 21

Relative atomic mass = very small roughly 0.0005

charge = -1

Question 22

Atomic number

Answer 22

the number of protons in an atom. The atoms in the periodic table are ordered by atomic number, which is the smaller number of each element.

Question 23

Mass Number

Answer 23

total number of protons and neutrons in the atom.

Question 24

Ion

Answer 24

an atom which has lost or gained electrons and has therefore become charged. A positive ion has lost electrons and a negative ion has gained electrons.

Question 25

Isotope

Answer 25

the atoms of the same number of protons so they are the same element, but with a different number of neutrons. Therefore, they have the same atomic number but a different mass number.

Isotopes have the same chemical properties, but they have different densities and can sometimes be radioactive.

Question 26

Maximum Electron shell numbers

Answer 26

2,8,8,18