Question

6 multiple choice 1 point
what forms a sigma (σ) bond?
○ sideways overlap of p orbitals
○ overlap of d orbitals only
○ direct overlap of orbitals along the axis between nuclei
○ sharing of three electron pairs
7 multiple choice 1 point
the octet rule states that atoms are most stable when they have:
○ eight valence electrons
○ only paired electrons
○ full d - subshells
○ ten valence electrons

Explanation:

Question 6:

To determine what forms a sigma (σ) bond, we analyze each option:

• "Sideways overlap of p orbitals" forms a pi (π) bond, not sigma.
• "Overlap of d orbitals only" is incorrect as sigma bonds can form from s, p, or hybrid orbitals, not just d.
• "Direct overlap of orbitals along the axis between nuclei" is the definition of a sigma bond (head - on overlap).
• "Sharing of three electron pairs" is a triple bond, which has one sigma and two pi bonds, so this is incorrect.

The octet rule is a chemical principle. We evaluate each option:

• "Eight valence electrons": The octet rule states that atoms are most stable when they have 8 valence electrons (like noble gases, except for some exceptions).
• "Only paired electrons": The octet rule is about the number of valence electrons, not pairing.
• "Full d - subshells": The octet rule is about s and p subshells (8 electrons in valence shell, ns²np⁶), not d - subshells.
• "Ten valence electrons": The octet rule is about 8 valence electrons, not 10.

Answer:

C. Direct overlap of orbitals along the axis between nuclei

Question 7: