Jill has a mixture of sand and iron filings. The mass of the mixture is 250 g. Jill uses a magnet to separate the two substances. Then, she measures the mass of the sand as 150 g. What should be the mass of the iron filings?
A.
100 g
B.
250 g
C.
It is impossible to determine.
D.
150 g

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.

Helium decays to form lithium. which equation correctly describes this decay?

Harry lives in a city, and he has a lung condition known as asthma. on certain days, harry has to stay inside because pollutants in the air make it difficult for him to breathe. which of these pollution sources are nonpoint sources that might bother harry if he goes outside? choose the two that apply.