Answer: half life
Explanation: Radioactive decay follows first order kinetics and the time required for the decay of a radioactive material is calculated as follows:

t= time required
k= disintegration constant
x= amount of substance left after time t
a= initial amount of substance
when one half of the sample is decayed, one half of the sample remains and t can be represented as 
at
, 


sorry but if you are looking for an answer I don't know one. :(
Answer: the distance of energy from point d to e
Answer:
Covalent, or, elements on the right side of the ladder (on the periodic table). Covalent compounds satisfy the octet rule by sharing electrons.
Hey :)
This time the answer is quantitive because the mentions numbers
Hope this helps!