Which of the following electron configurations belongs to an atom that is most likely to be involved in a
covalent bond?
a. 1s^22s^22p^63s^2
b. 1s^22s^22p^6
c. 1s^22s^22p^63s^23p^3
d. 1s^22s^22p^63s^23p^6
To determine which of the given electron configurations belongs to an atom that is most likely to be involved in a covalent bond, we need to understand the concept of covalent bonds.
A covalent bond is formed when two atoms share electrons to achieve a stable electron configuration. Typically, atoms that are close to filling or half-filling their outermost energy level tend to be involved in covalent bonding. This is known as the octet rule, which states that many atoms tend to gain, lose, or share electrons in order to acquire the stable electron configuration of having 8 electrons in their outermost energy level (except for hydrogen and helium, which follow the duet rule).
Now let's analyze each electron configuration given:
a. 1s^22s^22p^63s^2: This electron configuration represents the element magnesium (Mg) with 12 electrons. The outermost energy level (valence shell) is the 3rd energy level, which is not close to filling or half-filling. Magnesium is more likely to form an ionic bond, where it loses two electrons to achieve a stable electron configuration.
b. 1s^22s^22p^6: This electron configuration represents the element neon (Ne) with 10 electrons. The outermost energy level is the 2nd energy level, which is full with 8 electrons. Ne is a noble gas and is already stable with its full valence shell. It does not readily form covalent bonds.
c. 1s^22s^22p^63s^23p^3: This electron configuration represents the element phosphorus (P) with 15 electrons. The outermost energy level is the 3rd energy level, and it is one electron away from having a half-filled valence shell. Phosphorus is more likely to form covalent bonds.
d. 1s^22s^22p^63s^23p^6: This electron configuration represents the element sulfur (S) with 16 electrons. The outermost energy level is the 3rd energy level, and it is two electrons away from having a full-filled valence shell. Sulfur is also more likely to form covalent bonds.
Comparing options c and d, both phosphorus and sulfur are elements that can form covalent bonds, but phosphorus has one electron away from half-filling its valence shell while sulfur has two electrons away from full-filling its valence shell. Hence, option c (1s^22s^22p^63s^23p^3) is the electron configuration that belongs to an atom most likely to be involved in a covalent bond.