How many neutrons are probably in the nucleus of an element of atomic weight 197?
a. 43
b. 79
c. 83
d. 100
e. 118

Which conclusion fits the data in the table? a. heat chemically changes chocolate and margarine. b. all solids become liquid at 100°f. c. removing heat from a substance it to melt. d. matter may change shape when it is heated.

How can a mixture of salt water be separated into salt and water

Areaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is: