What happens to the mass of a sample containing a radioactive element during its half-life?

A. The mass decreases by half. B. The amount of mass is doubled. C. Eventually there is no mass at all. D. The mass remains the same.

N2 (g) + 202 (g) + 16.2 kcal → 2NO2 (g) Is it endothermic or exothermic?

Which is a unit of density? A) cm3/g B) g/cm C) g/cm3 D) ml/g

A chemical supply company sells a concentrated solution of aqueous h2so4 (molar mass 98 g mol-1) that is 50. percent h2so4 by mass. at 25°c, the density of the solution is 1.4 g ml-1. what is the molarity of the h2so4 solution at 25°c?

If the standard solutions had unknowingly been made up to be 0.0024 m agno3 and 0.0040 m k2cro4, would this have affected your results? how?

The gas phosphine (PH3) is used as a fumigant to protect stored grain and other durable produce from pests. Phosphine is generated where it is to be used by adding water to aluminum phosphide or magnesium phosphide.

Determine the number of moles 1) 20g Na and 2) 34g H2O

Nitrogen dioxide (NO2) gas and liquid water (H2O) react to form aqueous nitric acid (HNO3) and nitrogen monoxide (NO) gas. Suppose you have 5.0 mol of NO2 and 11.0 mol of H2O in a reactor. Suppose as much as possible of the NO2 reacts.

How long does it take the Earth to rotation and revive

What is Charles' law formula?

Which stars have the highest absolute brightness? Select one: a. Supergiants b. Giants c. Yellow stars d. Dwarfs