PLS HELP ASAP I DONT HAVE TIME AND IT ALSO DETECTS IF ITS RIGHT OR WRONG

The orientation of a plant or other organism in response to light, either toward the source of light (positive phototropism) or away from it (negative phototropism).

Explanation:

the way a plant or any other living organism moves as an reaction to light. there are 2 types of reactions, which is either towards light (positive phototropism) or away from the light (negative phototropism).

Explanation:

- 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