- Présentez-vous explain what is this .​

answer; i believe that the correct answer is (a) potassium(k)

- 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

to improve her experimental investigation, dalila should add a row in which no fertilizer is used. by a having a contrasting row in which no fertilizer is used, she will have a control group that will her understand the effects of the fertilizer in the plant developments vs the development of the plant when no fertilizer is used.