A chemical reaction produces formaldehyde, with a chemical formula of CH2O. Carbon is in Group 4A, oxygen is in Group 6A, and hydrogen is in Group 1A on the periodic table. In one to two sentences, describe the bonds in a molecule of formaldehyde in terms of valence electrons.

Answer 1

I have no idea what your teacher wants for this but here goes something.
C atom has 4 valence electrons, each H atom has two and the oxygen has 6 valence electrons for a total of 12 electrons. In H2C=O, C shares 2 electrons with EACH H atom, and four electrons with the oxygen atom. So there is a single bond between C and each H atom and a double bond between C and O. Said another way, C has four bonds (1 each with H and 2 with O). You can Google "Lewis electron dot structure of formaldehyde" and draw that. As I've described above you will use 12 electrons. For whatever it's worth, if I were teaching the class you could talk all day using words to describe the bonding but if you couldn't draw the Lewis electron dot structure I would not give any credit. Have a great new year.