What is the mass percent composition of an element in a molecule?

certain byproduct in nuclear reactors, 210Po, decays to become 206Pb. After a time period of about 276 days, only about 25% of an original sample of 210Po remains. The remainder has decayed to 206Pb. Determine the approximate half-life of 210Po.

Calculate the volume of liquid in the tank sketched below. Give your answer in liters, and round to the nearest 0.1 L. 5.1 cm 7.0 cm x ? 0.112 m

Two elements in the second transition series (Y through Cd) have four unpaired electrons in their 3 + ions. What elements fitthis description?

At a particular temperature, Kp 0.25 for the reaction a. A ask containing only N2O4 at an initial pressure of 4.5 atm is allowed to reach equilibrium. Calculate the equilibrium partial pressures of the gases. b.

Plumbers, welders, or glass blowers often use the gas propane (C3H8) because it burns in oxygen with a very hot flame. The products of the combustion of propane are carbon dioxide and water vapor.

The envelope of air that surrounds the earth is called

What is the chemical formula for potassium permanganate?

Is it always possible to identify something as an element compound pure substance or mixture

Why would someone weigh less on Pluto?

HNO3 + H2O > H3O (aq) + NO3 - (aq)