Answer:
To the best of my knowledge, it is because of the amount of gamma rays is given off.
Explanation:
While both are isotopes, Potassium 40 gives off fewer gamma rays compared to Cobalt 60. Potassium 40 isn't really harmful to humans, but Cobalt 60 (I believe) is used in chemotherapy.
The answer is D)
<span>when the remains of a living thing are preserved and turned into rock
</span>
No
Magnesium Chloride is MgCl2
The method I use to name ionic compounds is 'swap and drop'
Mg oxidation number is +2 and Cl oxidation number is -1
Mg^2+ Cl^-1
'swap'
Mg^1 Cl^2
'drop'
MgCl2
I would be inclined to go with A, C and D
