What units would you use to express a half-life?
items over time, such as atoms per second
mass over time, such as grams per minute
amount of time, such as minutes, hours, or years
volume over time, such as liters per minute
me

The unit is usually seconds. But it really depends on the situation you are in. If you are talking about uranium-238, then you'll be talking about a half life in the billions of years. However, if you are talking about the half-life of a muon, then it'll be in seconds or microseconds.

amount of time, such as minutes, hours, or years

Explanation:

I got it right on the test ;)

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

mass and volume are the answers you are looking for