An atom has a charge of 1+. If the atom's nucleus contains 23 protons, the atom must have A. 25 electrons. B. 22 electrons. C. 24 electrons. D. 23 electrons.

Option B.

Explanation:

The number of protons of an atom is equal to the atomic number (Z) and the number of electrons. When the atom lost or gain an electron, the number of electrons then changes and is different to the proton number.

When the atom gains an electron, then the atom will have the number of proton more one electron, and when the atom loose an electron, then the atom will have the number of protons less one electron.

Hence, the atom with 23 protons, must contains 23 electrons. But since the atom has a charge of 1+, that is to say, the atom has lost an electron, then the number of electrons of the atom is equal to:

Therefore, the correct answer is the option B, 22 electrons.

I hope it helps you!