Question

carbon compounds quick check
which option describes the structure of the electron shells in a neutral carbon atom? (1 point)
○ the inner shell is incomplete with three electrons. the outer shell is incomplete with three electrons.
○ the inner shell is complete with two electrons. the outer shell is incomplete with four electrons.
○ the inner shell is complete with three electrons. the outer shell is incomplete with three electrons.
○ the inner shell is complete with four electrons. the outer shell is incomplete with two electrons.

Explanation:

To determine the correct option, we recall the electron shell structure of a neutral carbon atom. The atomic number of carbon is 6, so it has 6 electrons. The first (inner) electron shell can hold a maximum of 2 electrons, and the second (outer) shell can hold up to 8. For carbon, the inner shell (n=1) has 2 electrons (complete), and the outer shell (n=2) has 6 - 2 = 4 electrons (incomplete, as it needs 8 to be full). Now we analyze each option:

• First option: Inner shell with 3 electrons (incorrect, inner shell should have 2), outer with 3 (incorrect).
• Second option: Inner shell complete with 2 electrons, outer shell incomplete with 4 electrons (matches our recall).
• Third option: Inner shell with 3 electrons (incorrect), outer with 3 (incorrect).
• Fourth option: Inner shell with 4 electrons (incorrect), outer with 2 (incorrect).

Answer:

B. The inner shell is complete with two electrons. The outer shell is incomplete with four electrons.