Which of the following could cause a physical change in a solid piece of sodium metal?

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

Ican determine the molar mass of an element by looking on the under the atomic mass for the element. for example the molar mass of phosphorus is 30.974 grams/mole. avogadro’s number tells me the amount of representative particles in 1 mole of any substance. this means 12.011 gram sample of carbon and a 32.0 gram sample of sulfur have the same number of atoms.

What is the effect of returning nuclear reactor cooling water back into bodies of water?