When you rub a match against a rough surface, fire results, giving off light and heat. The law of conservation of energy says that energy cannot be created. How can you explain the fire seeming to come from nowhere?

A student needs to determine the volume occupied by a gas in a 125 mL flask using the experimental setup described in the procedure. The student measures the volume of the flask to be 159 mL to the top of the flask.

What is the percent by mass of 5.0 g of nacl mixed with 80. g of water?

How does the state of matter affect the speed of sound

A copper cube has a mass of 420g and takes up 50.4cm^3 what is the density?

Why is pure water neutral

Molybdenum has a molar mass of 95.94g/mol. How many molecules of molybdenum are in 150.0 g of molybdenum

Describe a way that people might be able to solve each envioronmental problem listed below. coal mining can harm habitats and cause pollution.

A sample of methane gas occupies 4.50 gallons at a temperature of 80.0 F. If the pressure is held constant, what will be the volume of the gas at 100. degrees C?

Jack wants to know if it takes longer for warm water to freeze into ice cubes than cold water, so he performed the following experiment. Jack placed 50 mL of water in the refrigerator and allowed it to cool to a temperature of 4°C.

How to calculate average concentration