Year 9 - Exploring Chemical Reactions and Trends (level 10)

What is the significance of the rows (periods) in the periodic table?

• They indicate the number of valence electrons.

• They indicate the number of electron shells.

• They indicate the atomic mass.

• They indicate the reactivity of elements.

Which of the following is a characteristic of metals in the periodic table?

• High electronegativity

• Poor conductivity

• Malleability

• Brittle nature

• Synthesis

• Decomposition

• Displacement

• Combustion

Which of the following factors does NOT affect the rate of a chemical reaction?

• Temperature

• Colour of reactants

• Concentration

• Surface area

What is the trend in atomic size as you move down a group in the periodic table?

• It decreases.

• It remains the same.

• It increases.

• It fluctuates.

Which of the following reactions is exothermic?

• Melting ice

• Photosynthesis

• Combustion of petrol

• Evaporation of water

What is the effect of increasing the concentration of reactants on the rate of reaction?

• It decreases the rate.

• It has no effect.

• It increases the rate.

• It stops the reaction.

Which of the following elements is a non-metal?

• Sodium

• Iron

• Chlorine

• Aluminium

What is the main role of a catalyst in a chemical reaction?

• To increase the temperature

• To decrease the concentration

• To increase the reaction rate

• To change the products

Which of the following is a decomposition reaction?