What is mass?

A. the amount of matter in a substance

B. the amount of weight in a substance

C. the number of atoms in a substance

D. the amount of volume of a substance

How many half lives have passed if a sample contains one sixteenth of its original amount of radioactive material

The change in enthalpy is the change in heat energy of a reaction and is calculated by (Hint: Hess' Law) : Group of answer choices a. Sum of reactant enthalpies plus the sum of product enthalpies b.

Calculate the number of atoms in 23 g of sodium (Na).

What do a mole of magnesium (Mg) and a mole of iron (Fe) have in common?

Under what circumstances will a scientific theory be changed or discarded

Which of the following is the final concentration of KCl if 500 ml of 0.25 M KCl is diluted to a final volume of 5 L? 0.025 L 0.0025 L 25 L 2.5 L

What do you use to measure mass

A salt shaker filled with 17.0g sodium chloride contain how many moles?

When a radioactive decay occurs what is released? A. Only protons and neutrons B. Only electrons C. Protons/Neutrons, beta particle, gamma ray D. Only gamma rays

How is the process of scientific inquiry and the design process similar and how they are different.