What is the difference between a mixture and a substance

Calculate the total pressure in a 10.0 liter flask at 27°C of a sample of gas that contains 6.0 grams of hydrogen, 15.2 grams of nitrogen, and 16.8 grams of helium.

What has its own size and shape

Why isn't the atomic mass of most of the elements on the periodic table a whole number?

Amy is in a car moving quickly toward a stationary siren. Just as Amy moves past the siren, she notices a change in the _of the siren.

Chemists classify an element an element as a metal based on what physical properties

Do all organisms perform meiosis?

which one of these reactions is energy released? A all reactions B no reactions C endothermic reactions D exothermic reactions

Why do ionic compounds conduct electricity when dissolved in water but most covalent compounds do not?

Which of the following is an example of a molecule? F C Al O2

Organize the items listed into the proper sequence of events for gas exchange. a: O2 is transported to cells by circulatory system. b: O2 is drawn into the lungs during inhalation. c: Cells use O2 and generate CO2. d: CO2 is exhaled.