Question

a bond is formed when an electron is transferred from a sodium atom to a chlorine atom. what happens to the sodium atom during this process?

the mass of the atom increases.

the atom becomes an isotope.

the atomic number decreases.

the atom becomes a positive ion.

Explanation:

• When an electron is transferred from a sodium atom (\(Na\)) to a chlorine atom (\(Cl\)):
• The mass of an atom is mainly due to protons and neutrons in the nucleus. Since only an electron (which has negligible mass compared to protons and neutrons) is lost, the mass of the sodium atom does not increase.
• Isotopes are atoms of the same element with different numbers of neutrons. Here, the number of neutrons in sodium does not change, so it does not become an isotope.
• The atomic number is the number of protons in an atom. Sodium has 11 protons, and losing an electron does not change the number of protons. So, the atomic number does not decrease.
• A sodium atom (\(Na\)) has 11 electrons and 11 protons (\(Na:11p^{+},11e^{-}\)). When it loses one electron (\(e^{-}\)), it has 11 protons and 10 electrons (\(Na^{+}:11p^{+},10e^{-}\)). Since the number of protons (\(+ \)ve charge) is more than the number of electrons (\(-\)ve charge), it becomes a positive ion (\(Na^{+}\)).

Answer:

The atom becomes a positive ion.