Answer:
34 protons, 34 electrons, and 45 neutrons
Explanation:
Let's examine a periodic table. Locate where selenium is (see attachment).
First, the number of protons is represented by the atomic number, which is the whole number above the chemical formula, which is Se for selenium. We see it is 34, so there are 34 protons.
In any neutral element's atom, there are same numbers of protons and electrons. So, there are also 34 electrons.
Now, look at the decimal number below the chemical formula; it says 78.971, which we can round to about 79. This is the atomic mass, which is the sum of the number of neutrons and protons. We already know there are 34 protons, so there are:
79 - 34 = 45 neutrons
The answer is thus 34 protons, 34 electrons, and 45 neutrons.
~ an aesthetics lover
