Question

1. what are the three main subatomic particles in an atom?

o a) ions, molecules, atoms
o b) protons, neutrons, electrons
o c) neutrons, atoms, elements
o d) electrons, molecules, protons

1. what defines an element?

o a) the number of neutrons it has
o b) the number of electrons it has
o c) the number of protons it has

Explanation:

1. Atoms are composed of three main subatomic particles. Protons are positively - charged, neutrons are neutral, and electrons are negatively - charged. Ions are charged atoms or molecules, molecules are made of atoms, and elements are composed of atoms. So, the three main subatomic particles in an atom are protons, neutrons, and electrons.
2. The number of protons in an atom's nucleus defines an element. Different elements have different numbers of protons. The number of neutrons can vary (isotopes), and the number of electrons can change (ions), but the number of protons remains fixed for a given element.

Answer:

1. B. Protons, neutrons, electrons
2. C. The number of protons it has