An element has an atomic number of 78. the number of protons and electrons in a neutral atom of the element would be

78 and 78. An atom of the element has 78 electrons and 78 protons.

The atomic number is 78, so the atom has 78 protons (+).

If the atom is neutral, it must contain 78 electrons (-).

sorry idk the answer well to you i have a explaination

explanation: a formula which shows the arrangement of atoms in the molecule of a compound