what does entropy measure? a. entropy measures the total energy in a system b. entropy measures the disorder in a system c. entropy measures the latent heat of a substance d. entropy measures the heat capacity of a substance

Explanation:

Atomic number of sodium is 11 and it is a group 1 element. Hence, it is most reactive in nature.

Some properties of sodium are as follows.

It is one of the most chemically reactive metals.When it is not stored properly, sodium reacts explosively with air or water.

Atomic number of calcium is 20 and it is a group 2 element. Some properties of calcium are as follows.

Calcium is less reactive than sodium, but it is more reactive than most metals.Both sodium and calcium are always found as compounds in nature, and they are never present as elements.

Atomic number of iron is 26 and it is a d-block element. Therefore, it is also known as transition element.

Some properties of iron are as follows.

Iron also reacts with oxygen, but it does so over a period of time.When not protected by a coating then iron will gradually turn to rust, a compound of iron and oxygen.

Atomic number of gold is 79 and it is also a transition element. A property of gold is that it does not react easily with other substances.