An atom of the element iron has an atomic number of 26 and an atomic mass number of 56. if it is neutral, how many protons, neutrons, and electrons does it have?

26 protons, 26 electrons, 30 neutrons

Explanation:

Let P = protons, N = neutrons, E = electrons

The mass number of an atom is the sum of protons and neutrons in the nucleus of the atom.

The number of neutrons is the difference between the mass and atomic numbers of the atom

Therefore, 56 = P + N

where N = 56 - 26

N = 30

That means the number of neutrons is 30

To find P, 56 = P + N, N being 30

56 is now P + 30

56 = P + 30

56 - 30 = P

P = 26

Now, for an atom in its neutral state, the number of electrons is equal to the number of protons

Therefore, E is also 26

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.