Topic 1. Atomic Structure and the Periodic Table

Question 1

What are Protons?

Answer 1

Positively charged particles located in the nucleus.

Question 2

What are Neutrons?

Answer 2

Neutral particles are also found in the nucleus.

Question 3

What are Electrons?

Answer 3

Negatively charged particles that orbit the nucleus in electron shells.

Question 4

What is a compound?

Answer 4

Two or more elements chemically combined.

Question 5

What are Isotopes?

Answer 5

Atoms of the same element have the same number of protons but different number of neutrons.

Question 6

What are Mixtures?

Answer 6

Two or more elements not chemically combined.

Question 7

What are elements?

Answer 7

Pure substances consisting of only one type of atom.

Question 8

Give two examples of compounds.

Answer 8

Water (H₂O) and Sodium Chloride (NaCl)

Question 9

Give an example of an Isotope.

Answer 9

Carbon has isotopes such as Carbon-12 (6 protons, 6 neutrons) and Carbon-14 (6 protons, 8 neutrons).

Question 10

What is Chromatography?

Answer 10

A technique used to separate and identify components of a mixture based on their movement through a stationary phase while dissolved in a mobile phase.

Question 11

How do you calculate the Rf value in Chromatography?

Answer 11

By dividing the distance travelled by the component by the distance travelled by the solvent.

Question 12

What is Filtration?

Answer 12

A separation technique used to separate solids from liquids using filter paper.

Question 13

How is Filtration applied?

Answer 13

Commonly used to separate insoluble solids from liquids (e.g., sand from water).

Question 14

What is Crystallisation?

Answer 14

A process used to separate a soluble solid from a liquid by evaporating the liquid, allowing crystals to form.

Question 15

Name the steps in chronology of Crystallisation.

Answer 15

1. Dissolve the solute in a solvent to create a saturated solution.
2. Heat to evaporate some solvent until crystallisation begins.
3. Allow to cool for crystals to form.
4. Filter the crystals from the solution.

Question 16

What is Distillation?

Answer 16

A technique used to separate mixtures based on different boiling points.

Question 17

Describe the process of Distillation.

Answer 17

1. Heat the mixture to evaporate the component with the lower boiling point.
2. The vapour is then cooled in a condenser to form a liquid, which is collected separately.

Question 18

What is Distillation applied for?

Answer 18

Distillation is for Purifying liquids e.g. distilling seawater to obtain fresh water.

Question 19

What did Dalton’s Atomic Theory (1803) suggest?

Answer 19

It suggested that atoms are solid spheres and different elements consist of different atoms.

Question 20

What did JJ Thomson’s Model (1897) suggest and discover?

Answer 20

Discovered electrons; proposed the plum pudding model where electrons are embedded in a positively charged ‘soup.’

Question 21

What did Rutherford’s Gold Foil Experiment (1911) discover and lead to?

Answer 21

Discovered the nucleus, leading to the nuclear model of the atom.

Question 22

What did Bohr’s model (1913) propose?

Answer 22

Proposed that electrons orbit the nucleus in fixed shells.

Question 23

How are electrons arranged?

Answer 23

Electrons are arranged in energy levels or shells around the nucleus.

Question 24

What are Valence Electrons?

Answer 24

Valence electrons are electrons in the outermost shell of an atom that determine an element’s chemical properties and bonding behaviour.

Question 25

How did Dmitri Mendeleev arrange the first periodic table (1869)?

Answer 25

Ordered it by atomic mass, leaving gaps for undiscovered elements

Question 26

How is the Modern Periodic Table arranged?

Answer 26

It is arranged by atomic number. Groups represent elements with similar properties (e.g. Group 1: Alkali metals, Group 7: Halogens)

Question 27

How is Atomic Size of elements showcased in the periodic table?

Answer 27

It increases down a group and decreases across a period.

Question 28

How is the Ionisation Energy of elements showcased in the periodic table?

Answer 28

Generally increases across a period and decreases down a group.