How do you know an organism is a heterotroph? Can somebody help me with this if you know?

One mole of zinc has a mass of 65.4 grams. approximately how many atoms of zinc are present in one mole of zinc? 32 × 1023 atoms 6 × 1023 atoms 66 atoms 65 atoms

If 34.2 grams of lithium react with excess water, how many liters of hydrogen gas can be produced at 299 kelvin and 1.21 atmospheres? 2 li (s) + 2 h2o (l) yields 2 lioh (aq) + h2 (g)

What are the similarities of physical and chemical change ?