near what like open flames? if so false unless it clarifies the solution requires alcohol then its a no go
Answer : The half life of 28-Mg in hours is, 6.94
Explanation :
First we have to calculate the rate constant.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = time passed by the sample = 48.0 hr
a = initial amount of the reactant disintegrate = 53500
a - x = amount left after decay process disintegrate = 53500 - 10980 = 42520
Now put all the given values in above equation, we get


Now we have to calculate the half-life.



Therefore, the half life of 28-Mg in hours is, 6.94
ANSWER: C) Law of Conservation of Mass
EXPLANATION: In the given cycle, it is seen that th sediments are layered and gets compressed into sedimentary rocks which eventually gets heated and compressed to form metamorphic rocks. But, the total amount of minerals present in the sediments remains the same throughout any stage of the cycle.
This proves the law of conservation of mass which states that mass can not be created nor be destroyed, it can only be transferred from one form to another. So, in this case, only phase transition occurred but the component which is mineral inside the sediments remains constant.
Therefore, the answer is law of conservation of mass.