What causes a nucleus to become radioactive?

How have chemists affected our world for good? A. Chemists have caused many problems that our present society must face. B. Chemists have given us the atomic theory and the scientific method. C. Chemists have learned how dangerous chemicals can be D.

Why do helium-filled balloons float in air?

A substance that has a uniform composition and is able to be separated by physical means is?

Metals can be highly purified using electrolysis. Which equation best reflects the overall process of purifying copper? A. Cu^+2 (aq) cathode - --> Cu^+2 (aq) anode B. Cu^+2 (aq) anode - --> Cu^+2 (aq) cathode C. Cu (s) cathode - --> Cu (s) anode D.

How do i write a report about Gold mining?

Water (3030 g) is heated until it just begins to boil. If the water absorbs 5.49*105 J of heat in the process, what was the initial temperature of the water?

Identify the number of core and valence electrons for each atom. Xe : core electrons Xe : valence electrons Ca : core electrons Ca : valence electrons Br : core electrons Br : valence electrons

What do the lines around the finger of the doorknob represent?

Identify what type of reaction is below. Also determine what coefficients that would balance the chemical equation.

Much of life on Earth is based in aquatic biomes. What property of water allows life to survive in liquid water?