Answer:

Explanation:
The final answer has a different set of units. In particular, meters (m) changes to centimeters (cm). To make this change, you need to multiply the first value by proportions.
When writing these proportions, it is important that they are arranged in a way that allows for the cancellation of units. For instance, since m is located in the denominator, it must be located in the numerator of the conversion.
<u>Proportion:</u>
1 m = 100 cm
The full expression:
<h3>

·

=

</h3><h2> ^</h2>
As you can see, the old unit (m) cancels out and you are left with cm in the denominator.
the answer to your question is
volume
fourth period
The third period is similar to the second, except the 3s and 3p sublevels are being filled. Because the 3d sublevel does not fill until after the 4s sublevel, the fourth period contains 18 elements, due to the 10 additional electrons that can be accommodated by the 3d orbitals.