One isotope of sodium has 11 protons and 7 neutrons. What is the mass number of this isotope?

Lithium has 3 protons. How many neutrons are in the isotope Lithium-8?

What is the mass number of the isotope with the symbol ³⁷₁₇Cl?

Which of these refers to atoms with the same atomic number but different atomic masses?

The atomic number of fluorine is 9 and its atomic mass is 19. How many neutrons does fluorine have?

What is the mass number of the isotope with the symbol ³⁷Cl₁₇?

Lithium has 3 protons. How many neutrons are in the isotope Lithium-8?