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Explain how water droplets are found on the underside of the lunchbox cover.

Answer explanation

The water in the hot noodle soup evaporates to form water vapour. The warmer water vapour then rose and came into contact with the cooler underside of the cover to condense and form water droplets.

Why is the Sun important in the water cycle?

Answer explanation

The Sun provides heat for the water in the water bodies to evaporate and form water vapour.

Complete the following with X, Y or Z.

Condensation: _ to _

Evaporation: _ to _

Answer explanation

Z to X

Y to Z

What is the color of Liquid M?

Answer explanation

Colorless.

Explain how liquid M is collected in container X from boiling the red-colored water.

Answer explanation

The water in the red-coloured water gains heat from the flame of the Bunsen burner to boil and form steam. The warmer steam rises, comes into contact with the cooler underside of the metal tray, loses heat to it and condenses to form water droplets. The water droplets slide down the metal tray and drips into container X to be collected.

After some time, there were no more water droplets forming on the tray. Explain why.

Answer explanation

The metal tray gained heat from the warmer steam to become as warm as the steam. As there was no difference in temperature between the metal tray and steam, the steam was unable to lose heat to the metal tray to condense and form water droplets.

Explain clearly how the plant in the terrarium gets a continuous supply of water without being watered for two weeks.

Answer explanation

Water from the moist soil evaporated to form water vapour. Water is also lost through the stomata of the plant as water vapour. The warmer water vapour then rises and comes into contact with the cooler inner surface of the glass bottle, loses heat to it and condenses to form water droplets. The water droplets drip back into the soil and the cycle repeats itself.