Aflask contains 0.340 mol of liquid bromine, br2. determine the number of bromine molecules present in the flask.

  molecules

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number of particles.

1 mole of contains = molecules of bromine

0.340 mole of contains = molecules of bromine

Thus there are molecules of bromine present in the flask.

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