Which event always involves a chemical change?

boiling

melting

conducting

burning

An unknown volume of gas has a pressure of 0.50 atm and temperature of 325k. if the pressure is raised to 1.2atm and the temperature decreased to 320k giving a new volume of 48L what was the initial volume

Let's say we have 2 Zinc atoms and 2 Sulfur atoms on one side of the equation. According to the Law of Conversation and Mass, how many Zinc Sulfide molecules would be on the other side of the equation?

What adds air to flour before it is measured?

Which of the following wavelengths corresponds to light of the lowest frequency in this group? A. 454 nm B. 784 nm C. 342 nm D. 558 nm

When copper reacts with silver nitrate according to the equation, the number of grams of copper required to produce 432 grams of silver is - ?

How many grams of Cl are in 535 g of CaCl2?

2. An object experiences an acceleration, g, when it is on the surface of a planet of radius R. What will be the acceleration on the object after it has been moved to a distance of 4R from the center of the planet? A) 168 B) 48 C) 1/4 g D) 1/16 g

For a successful TLC experiment, you need to pay attention to the details. From the list of instructions and tips below, select the detail that is NOT important to a TLC experiment. O O Do not disturb the developing chamber.

The word atom means invisible?

A pycnometer weighs 25.60 g empty and 35.55 g when filled with water at 20°C. The density of water at 20°C is 0.9982 g/ml. When 10.20 g lead is placed in the pycnometer and the pycnometer is again filled with water at 20°C, the total mass is 44.83 g.