About 75% of living matter is made up of which two essential chemicals?

What is the best definition of chemistry? A. The study of mass, energy, and light B. The study of life and energy C. The study of experiments and theories D. The study of matter, its properties, and its reactions

Why can gamma rays pass through or penetrate solids? A. Gamma rays have low mass. B. Gamma rays have high mass. C. Gamma rays have low velocity. D. Gamma rays have high velocity.

How many grams are in 4.20 mol of sodium chloride (nacl) ? express your answer numerically in grams?

assuming gasoline can be represented as C8H18, how much oxygen is needed to completely burn this fuel. answer in grams of oxygen per gram of gasoline

Which atomic model was proposed as a result of J. J. Thomson's work? A. the plum pudding model B. the indivisible atom model C. an atom that had a lot of empty space D. an atom that had a concentrated nucleus

c. When we heat water up by the Bunsen burner, what temperature is the boiling water? After 10 minutes

Assuming that air contains 78 percent N2, 21 percent O2 and 1 percent Ar, all by volume. How many molecules of each type of gas are present in 1.0 L of air at STP?

Two children are playing tag. Child A who is doing the chasing can run 100m in 24 seconds Child B is running away from child A and can run 64m in 21 seconds.

What ion does a base increase

What is the definition of Amplitude?