Arithmetic - 30,-21,-12,-3

After 184.5 years, onky 0.625 grams of an original 20 gram sample of a radioactive isotope is left. Find the half life

A certain radioactive element has a half-life of one hour. if you start with 1.0 gram of the element at noon, how much of the radioactive element will be left at 2 p. m.? 0.50 grams 0.25 grams 0.125 grams 0.0 grams

N2 + H2 = NH4 Balanced or unbalanced

Which of the following statements is true? a. Acids and bases cannot mix together. b. Acids and bases will neutralize each other. c. Acids, but not bases, can change the pH of a solution. d.

What term describes matter that is a substance made of different kinds of atoms bonded together?

Common properties of sodium, calcium, iron, and gold

The closeness of a measurement to its actual value is a measure of its A. usefulness. B. reproducibility. C. precision. D. accuracy.

At 300 k the pressure inside a gas filled container is 500 kPa if the pressure inside decreses to 100kpa but the volume remains the same what is the final temperature of the gas

The SI unit for current is: joules volts ohms amps

In chemical reactions, there is a conservation of what?