Which of the following statements is(are) true?
I. The number of protons is the same for all neutral atoms of an element.
II. The number of electrons is the same for all neutral atoms of an element.
III. The number of neutrons is the same for all neutral atoms of an element.

Question

Which of the following statements is(are) true? 
I. The number of protons is the same for all neutral atoms of an element.
II. The number of electrons is the same for all neutral atoms of an element.
III. The number of neutrons is the same for all neutral atoms of an element.

Quizplus · Accepted Answer

Statement I is true because the number of protons in the nucleus determines which element the atom belongs to, and a neutral atom has equal numbers of protons and electrons.
Statement II is true because a neutral atom has equal numbers of protons and electrons.
Statement III is false because different atoms of the same element can have different numbers of neutrons, resulting in different isotopes.

Which of the Following Statements Is(are) True