Explain different between subscripts and coefficients

What is the percentage increased in the volume of a gas when the pressure is reduced to half at constant temperature?

How many atoms are in 159 g of calcium? 159 g =

The alcohol content of hard liquor is normally given in terms of the "proof," which is defined as twice the percentage by volume of ethanol (C2H5OH) present. Calculate the number of grams of alcohol present in 1.00 L of 48-proof gin.

He substance, cocl2, is useful as a humidity indicator because it changes from pale blue to pink as it gains water from moist air. What is its name?

Explain why more iron filings are located at the ends of the magnet than at the center of the magnet.

How will increasing the pressure on the system affect this equilibrium reaction? 2H2 (g) + O2 (g) - > 2H2O (g)

What are small round structures in the cell that breaks down large food particles into smaller ones

A balloon has a volume of 2.5 L and contains 0.100 moles of Helium. Another balloon has a volume of 5.0 L. They are at the same temperature and pressure. How many moles of gas does the second balloon contain?

Why is it important to that the solid be dry before the final mass measurement?

What is 0.00055030 in Scientific form?