10 days is twice the half-life. After 5 days, can expect

grams to remain; after another 5 days, you'd be left with

grams.
I think the answer is the 3rd rectangle but I'm not too sure I'm sorry
1= 12.2
8=97.6
and for the last one the answer is 10 :))
Answer: It will take 6 years for 7500 grams of X to reach 6900 grams.
Step-by-step explanation:
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.


b) for 7500 g to reach to 6900 g


It will take 6 years for 7500 grams of X to reach 6900 grams.
Every square is a rectangle because it is a quadrilateral with all four right angle (a rectangle is not a square)