If the half-life of a radioactive material is 8 years, how many years will it take for one-half of the original amount of material to decay?

It will take 8 years to decay one half of the original amount of the material.

Explanation:

Radioactive materials are those which emit radiations on decaying. So the decay of radioactive materials obey a exponential order.

Here, N is the number of radioactive materials present in time t, N₀ is the amount of radioactive material present at original state or at starting. Also k is termed as the disintegration constant and t is the time taken for decay.

So, disintegration constant is the rate at which the radioactive material will decay. In order to determine the time required to decay half of the original amount of radioactive materials, then we have to perform ratio of ln 2 to disintegration constant. This formula is defined as the half life time of the radioactive materials.

Thus, it can be stated as the time required to decay one half of the original amount of any radioactive material is defined as half life time of that material.

Since, here the radioactive material is said to have a half life time of 8 years, then it will require 8 years to decay one half of the original amount of the material.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.