Question

What is true of all atoms?

Option 1: They are electrically charged. (incorrect answer)
Option 2: They contain more than one electron shell. (incorrect answer)
Option 3: They have full outer electron shells. (incorrect answer)
Option 4: They contain at least one proton.

Answer 1

Atoms contain at least one proton and are electrically neutral when the number of protons equals the number of electrons.

Step-by-step explanation:

All atoms contain at least one proton.

Atoms are electrically neutral if they contain the same number of positively charged protons and negatively charged electrons. When the numbers of these subatomic particles are not equal, the atom is electrically charged and is called an ion.

The number of protons in an atom determines its element and is unique to each element. For example, carbon atoms have 6 protons in their nucleus, while tin atoms have 50 protons.