What describes how much of a substance has been dissolved into another substance and is usually expressed in a ratio or percent?

a.) solubility
b.)acidity
c.)concentration
d.)conductivity

oxygen, selenium, tellurium, and polonium.

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

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.