The process by which water vapor changes to liquid water is called

a. condensation.

b. evaporation.

c. freezing.

d. melting.

Why does an atom become negative when it gains an electron?

A scientist finds a piece of rock in a crater. He analyzes the rock and realizes that the composition is mostly of iron and nickel. He claims that he found a meteor. What is most likely the scientist's error?

You are to give ampicillin, with a recommended dose of 25 mg/kg, to a child with a mass of 26 kg. If stock on hand is 250 mg/capsule, how many capsules should be given?

A certain flexible weather balloon contains helium gas at a volume of 855 L. Initially, the balloon is at sea level where the temperature is 25°C and the barometric pressure is 728 torr.

A sample contains 1.29*1022 atoms of Cs. Calculate the amount of Cs.

Enter your answer in the provided box. A sample of an unknown gas effuses in 14.5 min. An equal volume of H2 in the same apparatus under the same conditions effuses in 2.42 min. What is the molar mass of the unknown gas

What volume will 0.710 moles of nitrogen gas occupy at STP?

4) Acompound has an empirical formula of Na2co3, and a molar mass of 3.18g/mol. Find its molecular formula.

How many molecules of glucose, C6H12O6, can be "burned" biologically when 283.2 grams of oxygen is a available?

Why does acids that has been accidentally spilled on a book cause the colour of the book cover and the ink to change?