Which of the following statements is false? Select one:

a. Atoms of the various elements differ in their number of subatomic particles.

b. All atoms of a particular element have the same number of protons in their nuclei.

c. The neutrons and protons present in the nucleus of an atom are almost identical in mass; each has a mass of about 1 dalton.

d. An atom is the smallest unit of an element that still retains the properties of the element.

e. Protons and electrons are electrically charged particles. Protons have one unit of negative charge, and electrons have one unit of positive charge.