Which of the following statements about macroions, large polyelectrolyte molecules, are true?a. These large molecules can often interact tightly with other molecules of opposite net charge. b. Concentrations of salts that mimic the ionic strength of cells tend to keep macromolecules in solution. c. Maximum solubility is achieved when the solution containing such a molecule is near the pI for that molecule. d. At high pH, macromolecules often carry net negative charges and therefore repel each other.

- 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

more infor would

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