Which of the following types of energy does an object store in the bonds of atoms and molecules? chemical energy gravitational energy kinetic energy sound energy

Hi!

The correct answer would be chemical energy.

Energy is classified into two basic categories:

Kinetic Energy

Potential Energy

Kinetic energy is possessed by objects or particles in motion, like waves or molecules as a system. Kinetic energy further includes sound energy (along with others not in listed in the question)

Potential energy is the energy that is reserved/stored or possessed by an object in a particular position. Potential energy further includes gravitational and chemical energy (along with others not in the question)

The energy between bonds is a form of potential energy, as energy is stored in the bonds. The energy stored in the bond is associated with the position of the atoms in relation to one another and the structure of the molecule.  

Hope this helps!

b is the correct

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