The half-life of radon-222 is 3.824 days. after what time will one-fourth of a given amount of radon-222 remain?

7.648 days.

Explanation:

Half-life is the time for a sample reduce its amount to the half.

The radioactie isotopes, such as radon-222, have constant half-life times.

The amount that remains after a number, n, of half-lives may be calcualted by the following exponential decay equation:

From which you get:

Here, you want A/A₀ = 1/4

So, you just must to solve for n:

Then, two half-lives will have passed, which equals to 2×3.824 days = 7.648 days.

There is one s orbital, and there are three p orbitals, five d orbitals, and seven f orbitals. thus, the answer is b. do not confuse the number of orbitals in a subshell with the number of electrons the subshell can hold. each orbital can hold two electrons, so the capacity of an nf subshell is 14 electrons.

Idont know. if you want an answer you need to give us some context dude.