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
, 


Magnesium(?)
<span>2 HCl + Mg ? MgCl2 + H2</span>
Answer:
B. double-replacement RXN
Explanation:
more specifically, this is a precipitation rxn.
Answer:
Explanation:
A. White blood cells have many lysosomes because they need to produce a lot of glucose and oxygen.
Lysosomes are found in all animal cells, but are most numerous in disease-fighting cells, such as white blood cells. This is because white blood cells must digest more material than most other types of cells in their quest to battle bacteria, viruses, and other foreign intruders.