1 This question is about the Earth and its atmosphere.
Figure 1 shows the Earth and its atmosphere billions of years ago.
The boiling point of water is 100°C.
Suggest one reason why there was no liquid water on the Earth's surface billions of
years ago.

Earth's early
atmosphere of:
• carbon dioxide
• water vapour
• methane
• ammonia

water vapour

Explanation:

allow the Earth’s surface

temperature was too/very hot

or water evaporated/ boiled

or turned to steam/gas

allow because of heat from

volcanoes

ignore the Earth’s surface

was covered by volcanoes

ignore water turned to water

vapour

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.