Question

question 7
how many electrons are in the valence shell of an uncharged magnesium atom?

question 8
0.5 pts
which of the following covalent bonds would you expect to be polar? choose all that apply.
o-h
c-h
n-h
o=o
c=o
c-c

Explanation:

Step1: Recall magnesium's atomic number

Magnesium (Mg) has an atomic number of 12.

Step2: Write electron - configuration

The electron - configuration of Mg is 1s²2s²2p⁶3s². The outermost shell is the third shell (n = 3), and it has 2 electrons. So, the number of valence electrons in an uncharged magnesium atom is 2.

Step3: Understand polar bond concept

A polar covalent bond occurs when there is a significant difference in electronegativity between the two atoms in the bond.

Step4: Analyze each bond

• For O - H: Oxygen (O) has an electronegativity of 3.44 and hydrogen (H) has 2.20. There is a significant electronegativity difference, so it is polar.
• For C - H: Carbon (C) has an electronegativity of 2.55 and hydrogen (H) has 2.20. The electronegativity difference is relatively small, but it is still polar to some extent.
• For N - H: Nitrogen (N) has an electronegativity of 3.04 and hydrogen (H) has 2.20. It is polar due to the electronegativity difference.
• For O = O: Both atoms are the same (oxygen), so the electronegativity difference is 0, and it is non - polar.
• For C = O: Carbon (C) has an electronegativity of 2.55 and oxygen (O) has 3.44. It is polar.
• For C - C: Both atoms are the same (carbon), so the electronegativity difference is 0, and it is non - polar.

Answer:

Question 7: 2
Question 8: O - H, C - H, N - H, C = O