True or false If a material has a hardness of 8, it cannot be scratched by a material with a hardness of 7.

A camper burned a piece of paper to start a campfire. is burning paper a physical or chemical change? why? If you said chemical, what are the reactants and products? The ash has less mass than the paper, was mass conserved during the reaction?

The change in entropy, Δ S ∘ rxn, is related to the the change in the number of moles of gas molecules, Δ n gas.

Compared to a 26-gram sample of NaCl (s) at STP, a 52-gram sample of NaCl (s) at STP has (1) a different density (2) a different gram-formula mass (3) the same chemical properties (4) the same volume

Are The Flowers in a Flower Arrangement Alive?

Which of the following statement is true about a compound

You transfer a sample of a gas at 17°C from a volume of 5.67 L and 1.10 atm to a container at 37°C that has a pressure of 1.10 atm. What is the new volume of the gas?

What is true about the energy involved in a chemical reaction? A. The amount of energy is constant, but it is converted from one form to another. B. The amount of energy decreases as it is converted from one form to another. C.

Which state of matter is highly compressible, is made of particles moving independently of each other, and is present in large quantities near Earth's surface?

The air in an inflated balloon (the system) absorbs 125 J of heat from its proximity to a fire. The balloon expands and does 85 kJ of work. What is the change in internal energy (in kJ) (ΔU) for the system? Round to the nearest whole number.

Is a cytoplasm made of 80 percent of water