EVERYDAY SCIENCE

Detailed explanation-1: -If the mass number is 18 and the atomic number is 10 (number of protons) then there are 10 protons and 8 neutrons (18−10=8).

Detailed explanation-2: -Oxygen has an atomic number of 8, meaning it has eight protons. The mass number of the atom is given after the element name when identifying the isotope, thus the mass number of oxygen-18 is 18. When we subtract the 8 protons from the mass number 18, we are left with 10 neutrons.

Detailed explanation-3: -The Oxygen (O) has an atomic number of 8 and has a mass number of 16. Upon accepting 2 electrons it becomes O2-. The mass number is defined as the sum of the number of protons and neutrons present in the molecule. So here for O2-it contains 8 protons, 8 neutrons and 10 electrons.

Detailed explanation-4: -Looking at the nuclide symbol for oxygen-18, we can recognize that O is the chemical symbol of oxygen, 18 is the mass number, and eight is the atomic number.