The answer is D) a neutron.
When we say an atom's mass is, like 5 atomic mass units actually we are saying that the total number of the neutrons and protons in its nucleus is 5.
The mass of a neutron and a proton is each one atomic mass unit.
Mass of a neutron is approximately 1 atomic mass unit.
Standard Molar Volume is the volume occupied by one mole of any gas at STP. Remember that "STP" is Standard Temperature and Pressure. Standard temperature is 0 &176:C or 273 K. Standard pressure is 1 atmosphere or 760 mm Hg (also called "torr"). 1 mole of any gas at STP occupies 22.4 liters of volume.
Sulfur has 6 electrons, so we put 6 in the first spot.
Oxygen has 6 electrons too, but since there are 3, we would multiply 6 times 3 , which equals 18, then add that too.
The 2 is added because there is that negative 2 at the top of the formular, which indicates the presence of two extra valence electrons.
the equation would be
6 + 18 + 2 = 26
