What is the approximate bond angle around the central carbon atom in acrolein?

The approximate bond angle around the central carbon atom in acrolein is 120°.

Explanation:

The structure of acrolein is shown in the attachment. From the structure, we can deduce that the central carbon atom is in an sp2 hybridization (Atoms with a double bond hybridize in an sp2 fashion).

Atoms with sp2 hybridization have trigonal planar geometry, in this kind of hybridization, bonds are oriented the farthest away possible from each other, to minimize overlapping and the angle that allows that is 120°. 

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms

answer; talc and gypsum;