15. the dense, central core of the atom containing protons and neutrons is the _________.\n16. the total…

15. the dense, central core of the atom containing protons and neutrons is the _________.\n16. the total number of protons and neutrons in an atom is the _________.\n17. a type of particle consisting of two protons and two neutrons (essentially a helium nucleus) is called an _________.
Answer
Brief Explanations:
- By definition, the dense, central core of an atom with protons and neutrons is the nucleus.
- The sum of protons and neutrons in an atom gives the mass - number.
- A particle with two protons and two neutrons (like a helium nucleus) released from an unstable nucleus is an alpha - particle.
Answer:
- nucleus
- mass - number
- alpha - particle