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.

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).

I hope it will help you

by cartels in other countries, shipped by air, mail, or land. i cant really see your answer choices : /

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.