When the amount of a radioactive substance is reduced by 50%, what has occurred?

gamma radiation

alpha radiation

a half-life

beta radiation

A volume of gas occupies 1.2 L at 5.1 kPa. What volume would the gas occupy at 2.2 kPa?

In the chemical equation Zn + 2HCl ZnCl2 + H2, the reactants are A. zinc and hydrochloric acid. B. zinc and hydrogen carbonate. C. zinc chloride and hydrogen. D. zinc chlorate and water.

Definition: One of a class of elements having properties intermediate to metals and nonmetals.

Which phrase describe typcal features of plains? Check all that apply A. usually have a low relief B. have steep sides C. usually have a high elevatio D. can be interior E. can be coastal

A kettle has a store of 400J of thermal energy in the heating filament. 345J is transferred by heating to thermal energy store of water. How much energy is dissipated as sound?

Is it possible for a balloon with an initial internal pressure equal to 250.0 kPa to naturally expand to four times its initial volume when the temperature remains constant and the atmospheric pressure is 101.3 kPa?

How many atoms of gold (Au) are present in a sample of 2.5 mol Au? A. 1.5 * 1024 atoms Au B. 1.5 * 1023 atoms Au C. 4.2 * 1024 atoms Au D. 4.2 * 1023 atoms Au

what might cause the goldfish population to drop if the temperature moves out of its normal range? Name three things

Why must a chemistry experiments performed in a well ventilated room?

What kind of chemical bond does salt have?