Development of the Periodic Table Practice Questions

Question 1

Q1 (2 marks)

Define isotopes and explain how they differ from one another.

Question 2

Q2 (2 marks)

State the Law of Octaves and explain how it was used in the development of the periodic table.

Question 3

Q3 (3 marks)

Explain why Group 1 elements are highly reactive.

Question 4

Q4 (3 marks)

Describe the trend in electronegativity across a period of the periodic table. Explain this trend in terms of atomic structure.

Question 5

Q5 (4 marks)

Calculate the relative atomic mass of an element X, given the following isotopic data:

- Isotope 1: mass number 24, abundance 80%

- Isotope 2: mass number 25, abundance 20%

Question 6

Q6 (4 marks)

Write a balanced chemical equation to show the reaction between sodium and chlorine. Identify the reactants and products as elements and compounds.

Question 7

Q7 (3 marks)

The table below shows data for the first 10 elements in the periodic table.

Element

Atomic Number

Atomic Radius (pm)

Hydrogen

1

53

Helium

2

31

Lithium

3

155

Beryllium

4

111

Boron

5

85

Plot a graph of atomic radius against atomic number. Describe the trend observed.

Question 8

Q8 (3 marks)

Explain how the periodic table has been used to develop new materials, such as plastics and semiconductors.

Question 9

Q9 (3 marks)

Discuss the importance of the periodic table in understanding and predicting the properties of elements and their compounds.

Question 10

Q10 (3 marks)

How has the periodic table contributed to our understanding of the chemical reactions that occur in everyday life?

- Isotopes are atoms of the same element with the same atomic number (1) but different mass numbers (1).

- Law of Octaves: "Every eighth element has similar properties" (1).

- Used to group elements with similar properties into families (1).

- Group 1 elements have one valence electron (1).

- Valence electrons are easily lost (1).

- Loss of electrons leaves a positive ion (1).

- Electronegativity increases across a period (1).

- Due to increasing proton number (1), which attracts electrons more strongly (1).

- Isotope 1: 24 × 0.8 = 19.2

- Isotope 2: 25 × 0.2 = 5.0

- Relative atomic mass = (19.2 + 5.0) / 100 = 24.2 (4)

- 2 Na + Cl2 → 2 NaCl

- Reactants: Na, Cl2

- Products: NaCl

- Plot a graph of atomic radius against atomic number (1).

- Trend: Atomic radius decreases across the period (1).

- Plastics: Polythene and polystyrene are based on carbon and hydrogen (1).

- Semiconductors: Silicon used in solar panels (1).

- Predicts reactivity (1), properties of compounds (1), and trends in physical properties (1).

- Explains reactions in batteries (1), combustion (1), and acid-base reactions (1).

Carbon

6

70

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