<u>Complete Question:</u>
Which statement best describes why liquid water exists on earth?
A. Earth experiences comet crashes and volcanic eruptions.
B. Earth experiences a strong magnetic field and lunar tides.
C. Earth has moderate temperatures and a strong gravitational force.
D. Earth has hydrogen bonds with the sun
<u>Correct Answer:</u>
Earth has a moderate temperature and strong gravitational force. This is the reason for existence of liquid water on Earth.
<u>Step-by-step explanation:</u>
Liquid water has the chemical formula of H₂O. So it is composed of mainly hydrogen and oxygen molecules with the present of different materials present in it based on the place it is located. As the water molecules are bonded by weak van der waals bond, it can be easily broken with the boiling point of 100 °C.
Thus, the existence of liquid water is possible in moderate temperature. Also the strong gravitational force of Earth helps to keep the liquid water stable in Earth. Thus, the strong gravitational force and the moderate temperature condition of Earth is responsible for liquid water existence on Earth.
