Answer is: 2. atomic number.
Atomic number is unique and defines an element. Atomic number (Z) is total number of protons in an atom.
For example, nitrogen atom (N-14) has 7 protons (p⁺), 7 electrons (e⁻) and 7 neutrons (n°). Protons (positive charge) and neutrons are in the nucleus of atom, electrons (negative charge) are bound to the nucleus in spherical shells. Nitrogen is an element with atomic number 7. Mass number (A) is the total number of protons and neutrons in a nucleus. Nitrogen mass number is 14 (A = p⁺ + n°; A = 14).
if i am correct it shall be 12. because i am thinking, 1 mole = 1 ar.
Answer:
its an asteroid
and it seems to be same as picture and what I knew
have a great time
The answer is Ra
Atomic number for Be is 4
Atomic number for Mg 12
Atomic number for Ra 88
Atomic number for Ba 56
