An element has an atomic number of 78. The number of protons and electrons in a neutral atom of the element are
A) 156 protons and 78 electrons.
B) 39 protons and 39 electrons.
C) 78 protons and 0 electrons.
D) 78 protons and 78 electrons.
E) 78 protons and 39 electrons.

Question

Quizplus · Accepted Answer

The number of protons an element has is called the atomic number. In a neutral atom, there are the same number of protons and electrons. Protons carry a positive charge. Because neutral atoms have no charge, there must be an equal number of negative charges electrons).

An Element Has an Atomic Number of 78