A water strider (water bug) is able to walk on water because of water’s...

Surface tension

Explanation:

A water strider (water bug) is able to walk on water because of water’s Surface tension.

Surface tension is phenomenon in which in liquid where it shrinks itself to its minimum surface area possible, it is very much visible in water surface because of high attraction between the water molecule.

- 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

it's filtration, but this is an assumption so my apologies if i got this