Answer: a. water cycle
Explanation:
A water cycle can be define as the cycle of water in which water in various states like solid, liquid and gaseous forms circulates in different spheres of the earth. It describes how water evaporates from the surface of earth, the water vapors accumulate in the atmosphere, these water vapors become cool and condense in the form of rain or other kind of precipitations. The water cycle plays an important role in changing the weather condition of a region.
The average kinetic energy of colliding particles can be increased by increasing temperature.
B.
For example, ionic compounds, which are very polar, are often soluble in the polar solvent water. Nonpolar substances are likely to dissolve in nonpolar solvents. For example, nonpolar molecular substances are likely to dissolve in hexane, a common nonpolar solvent.
CaO because oxygen have 2 dots and calcium as well
(oxygen valency -2
calcium valncy +2)= CaO
Water is one of the few substances which expand in volume when frozen, compared to liquid. Usually substances condense when cooled, but at the point of freezing, when liquid water becomes solid ice, the molecules lock into a matrix in which there is more space between molecules - ice expands! This is why ice floats on liquid water.
It is this miracle which has shaped the planet and allowed life to thrive. Expansion of ice is responsible for much land-shaping erosion on land, the heaving off of boulders from mountain tops. And the floating of ice on lakes, rivers and oceans - if the frozen water was indeed more dense than liquid water, it would sink and pile up in the cold depths. There would be no life thriving under the ice, overwintering. It would all eventually freeze solid, and all the life forms with it.
