5H2 :How many atoms of Hydrogen are in this formula?

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.

4. propanol and isopropanol are isomers. this means that they have a) the same molecular formula but different chemical properties. b) different molecular formulas but the same chemical properties. c) the same molecular formula and the same chemical properties. d) the same molecular formula but represent different states of the compound

What is the scientific name for weight?