You’re an undergraduate researcher preparing reagents for one of your experiments. You need to make a stock of phosphate-buffered saline (PBS) solution and are following the manufacturer’s instructions, which state that to make 1 L of 10X PBS, you will need to combine 100.0 mM disodium hydrogen phosphate (Na2HPO4), 18 mM potassium dihydrogen phosphate (KH2PO4), 1.37 M sodium chloride (NaCl), and 27 mM potassium chloride (KCl) to an Erlenmeyer flask, before bringing the final volume to 1 L with deionized water.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.