The number of grams of radon 222 did it have 15.2 ago was 49.6 grams( answer C)
<u>calculation</u>
- calculate the number of half life it has covered from 15.2 days to 3.8 days
that is divide 15.2/ 3.8 = 4 half life
- half life is time taken for a radio activity of a specified isotope to fall to half its original mass
therefore 3.8 days ago it was 3.1 x2 = 6.2 grams
7.6 days ago it was 6.2 x2 = 12.4 grams
11.4 days ago it was 12.4 x2= 24.8 grams
15.2 days ago it was 24.8 x2=49.6 grams
Hello There!
A Heat Pack is An Example Of A Endothermic Process.
An Endothermic Reaction Is A Reaction That Requires Energy To Move Forward.
<span>a regultate is to control or direct by a rule, principle, or method.</span>
A gland is an organ that excretes chemical fluids to discharge into the surroundings or for use in the body.
Answer:
6 elements.
Explanation:
99.9% by weight of most living things is made of the six elements: hydrogen, carbon, nitrogen, oxygen, phosphorus, and sulfur (backwards using just the letter abbreviations this spells SPONCH).