The half-life of a radioactive isotope is 20.0 minutes. What is the total amount of a 1.00-gram sample of this sample of this isotope remaining after 1.00 hour?

A japanese sword maker heats a mixture of iron and charcoal. he repeatedly heats, folds and flattens the mixture more than a thousand time. what is he doing

How many moles of Al (CN) 3 are in 217 g of the compound?

All are ways to combat water pollution except

4.8 kg of sulfur dioxide contains how many molecules?

How many atoms are present in 34.228 g of sodium

Which statements about isozymes are true? Isozymes catalyze different reactions. Isozymes have identical kinetic properties. Isozymes are present in various developmental stages. Isozymes are encoded by the same gene.

A fog over a lake. what two changes of state must occur to produce the fog? do the water molecules absorb or release energy during these changes of state? what happens to the motion of the water molecules as a result?

Limes have a [H3O+] of 1.3 x 10-2 mol/L. Their pOH is

The human body is 0.0040% iron. How many milligrams of iron does a 165 pound person contain?

Which of the following is the correct Lewis structure for ammonia (NH3) ? Note: Hydrogen and nitrogen have one and five valence electrons respectively.