Revision 9

Part of the Periodic Table is shown.

Which numbers represent a metal and a non-metal in the same period?

• 1 and 2

• 2 and 3

• 4 and 6

• 5 and 6

Answer explanation

In period 2, element 5 (Boron) is a metalloid and element 6 (Carbon) is a non-metal. Thus, 5 and 6 represent a metal and a non-metal in the same period, making this the correct choice.

Which row describes elements in Group I and Group VII of the Periodic Table?

• A

• B

• C

• D

Answer explanation

Group I elements are alkali metals, known for being highly reactive, while Group VII elements are halogens, also very reactive. Answer A correctly describes these characteristics, making it the right choice.

Which statement describes an alloy?

• It is a compound containing a metal and a non-metal.

• It is a compound containing two metals.

• It is a mixture of a metal with other elements.

• It is a pure metal.

Answer explanation

An alloy is defined as a mixture of a metal with other elements, which can include other metals or non-metals. This distinguishes it from pure metals and compounds, making the correct choice the one that describes it as a mixture.

Butane is a hydrocarbon.

What are the products of the complete combustion of butane?

• carbon and hydrogen

• carbon dioxide and hydrogen

• carbon dioxide and water

• carbon dioxide only

Answer explanation

The complete combustion of butane (C4H10) produces carbon dioxide (CO2) and water (H2O) as the main products. This occurs when butane reacts with oxygen, releasing energy and forming these two compounds.

A student determines the volume of a laboratory notebook.

Which measuring instruments are used?

• a clock and a measuring cylinder

• a measuring cylinder and a ruler

• a measuring cylinder only

• a ruler only

Answer explanation

To determine the volume of a laboratory notebook, a ruler is sufficient to measure its dimensions (length, width, height). A measuring cylinder is not needed as it is used for liquids, not solid objects like a notebook.

A student wants to find the period of a pendulum. He determines the time taken for the pendulum

to make one complete oscillation. He repeats the measurement several times.

His results are shown in the table.

What is the average value for the period of the pendulum?

• 1.4 s

• 1.5 s

• 1.7 s

• 9.0 s

Answer explanation

To find the average period, sum all measured times and divide by the number of measurements. The average of the given results is 1.5 s, which is the correct choice.

Graph 1 is a distance–time graph. Graph 2 is a speed–time graph.

Which graphs represent the motion of a car that is moving at constant speed?

• both graph 1 and graph 2

• graph 1 only

• graph 2 only

• neither graph 1 nor graph 2

Answer explanation

A car moving at constant speed would show a straight line in the distance-time graph (Graph 1) and a horizontal line in the speed-time graph (Graph 2). Since neither graph shows these characteristics, the correct answer is 'neither graph 1 nor graph 2'.

A cart is pulled along a horizontal road by a horse.

The horse does work on the cart. The work done depends on the force exerted on the cart and on one other quantity.

What is the other quantity?

• the distance between the horse and the cart

• the distance moved by the cart

• the height of the horse

• the weight of the cart

Answer explanation

The work done by the horse on the cart is calculated as the product of the force exerted and the distance moved by the cart. Therefore, the other quantity that affects the work done is the distance moved by the cart.

Which energy resource is non-renewable?

• geothermal

• hydroelectric

• nuclear

• wind

Answer explanation

Nuclear energy is considered non-renewable because it relies on finite resources like uranium. In contrast, geothermal, hydroelectric, and wind energy are renewable resources that can be replenished naturally.

Some of the liquid in a beaker starts to evaporate.

What happens to the temperature of the liquid remaining and why does the temperature change?

• The temperature decreases because more-energetic molecules escape.

• The temperature decreases because there are fewer molecules remaining.

• The temperature increases because less-energetic molecules escape.

• The temperature increases because there are fewer molecules remaining.

Answer explanation

The temperature decreases because more-energetic molecules escape during evaporation. As these high-energy molecules leave, the average kinetic energy of the remaining molecules decreases, leading to a lower temperature.