The half-life of tritium or hydrogen-3 is it 12.32 years, after about 24.6 years how much of a sample of tritium remain unchanged?
a 1/3
b 1/2
c 1/8
d 1/4

The answer will be D, 1/4.

How you come to this conclusion( for future reference to anyone stuck on this ), is figure out how many half-lives have passed. In this case two half-lives have passed ( 24.6 is 12.32 + 12.32 ), so just put into your calculator 1/2 x 1/2 ( or .5 x .5 ). Make sure your answer is in fraction form, and you have your answer! Hope this helps any who may see this!

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.

cells spend most of their time in interphase