How can you tell from a substance's formula if it is ionic or molecular?

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?

What is the area in square meters of 448 g ai foil that has a thickness of 23921 nm? the density is 2.70 g/cm

Which elements are found in glucose, the product of photosynthesis? a. carbon, hydrogen, and oxygen b. carbon and hydrogen c. carbon, nitrogen, and oxygen d. hydrogen, nitrogen, and carbon