8. What is the mass of a sample of glass (specific heat = 0.50 J/g°C), if it requires 490 J of heat to raise the temperature from -18.0°C to 0.0°C?

it should be all of them because it asks if you included all of those in your answer

explanation:

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).

what is the question?

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