How do you know a chemical reaction has occurred in a candle?

What is the indicator of the number of ions in solution? the amount of conductivity the amount of precipitate the amount of solute added

Which of these statements best explains why space exploration should be encouraged? it prepares humans to live without oxygen. it dispel myths about objects in space. it prevents comets and asteroids from striking earth. it creates technology to absorb harmful radiations in space.

The molar mass of nickel(ni) is 58.7 g/mol. how many moles are in an 88 gram sample of nickel?