Aspecific radioactive isotope is presented for our scientific evaluation for possible use of this isotope within the field of radioisotopic medical tracers. at 1 pm, there are 5.6 grams and at 7 pm, there are 3.2 grams. what's the half-life? a) about 3.2 hrs b) about 7.4 hrs c) about 17.1 hrs d) over 24 hrs

B)about 7.4 hrs

Explanation:  

Rate law expression for first order kinetics is given by:

where,

k = rate constant

t = time taken for decay process =6 hours

a = initial amount of the reactant = 5.6 g

a - x = amount left after decay process = 3.2 g

Putting values in above equation, we get:

To calculate the half life, we use the formula:

answer: cellular respiration takes in food and uses it to create atp, a chemical which the cell uses for energy. usually, this process uses oxygen, and is called aerobic respiration. it has four stages known as glycolysis, link reaction, the krebs cycle, and the electron transport chain.