what is most likely true of an atom with a mass of 15 amu? there are 15 protons. there are 15 electrons. the…

what is most likely true of an atom with a mass of 15 amu? there are 15 protons. there are 15 electrons. the total number of protons and electrons is 15. the total number of protons and neutrons is 15.

what is most likely true of an atom with a mass of 15 amu? there are 15 protons. there are 15 electrons. the total number of protons and electrons is 15. the total number of protons and neutrons is 15.

Answer

Explanation:

Step1: Recall atomic - mass concept

The atomic mass (in amu) of an atom is approximately equal to the sum of the number of protons and neutrons in the nucleus of the atom. Protons and neutrons each have a mass of approximately 1 amu, while electrons have a negligible mass compared to protons and neutrons.

Step2: Analyze each option

  • Option 1: Having 15 protons would mean the atomic number is 15, but the mass is determined by protons + neutrons, not just protons.
  • Option 2: Electrons have a very small mass and do not contribute significantly to the atomic mass.
  • Option 3: Protons and electrons do not determine the mass; it's protons and neutrons.
  • Option 4: This is correct as the atomic mass is the sum of protons and neutrons.

Answer:

The total number of protons and neutrons is 15.