Which of the following might a chemist choose to study? a. glacier movement in alaska b. better ways to recycle plastics c. the effects of hurricanes on turtle populations d. the vibrations in bridges caused by big trucks

C. better ways to recycle plastics

Explanation:

B. Better ways to recycle plastics

Explanation:

Remember that chemistry studies matter and energy as well as the interactions between them. This means it studies the changes that material substances undergo, how and why substances combine or separate to form another ones. In this case the action of recycling implies a chemical change as the plastic transform not only in a physical way but in a structural one.

This is the reason a chemistry would probaly studie the most efficient way to do it, this means, the way it needs less energy to change.

part 1: the half-life of the element is 22 years.

part 2: it will take 132.02 year for the sample to decay from 308.0 g to 4.8125 g.

explanation:

part 1: there are two ways to determine the half life time.

first way: the half life time can be determined directly from its definition as it is the time required for the sample to decay to its half concentration.

from the data the initial concentration was 45.0 g and decayed to its half value (22.5 g) in 22.0 years.

second way: the radio active decay is considered first order reaction so we can use the laws of first order reactions.

k = (1/t) ln (a/a-x), where k is the rate constant of the reaction,

t is the time of the reaction

a is the initial concentration of the reactant

a-x is the remaining concentration at time (t)

a = 45.0 g the initial concentration at t = 0 year.

at t = 22 year, a-x = 22.5 g

then k = (1/22 year) ln (45.0 g/ 22.5 g) = 0.0315 year-1.

the half-life time (t1/2) = ln 2/ k = 0.693/ k =0.693/ 0.0315 = 22 years.

part 2:

using the same law k = (1/t) ln (a/a-x),

using the given data; a = 308.0 g and a-x = 4.8125 g and the calculated k from the part 1 (k = 0.0315 year-1)

t = (1/k) ln (a/a-x) = (1/0.0315) ln (308.0/ 4.8125) = 132.02 years

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements