How many atoms are in 5.548 g of thorium

How many joules are absorbed when 83.2 grams of water is heated from 30.0 °C to 74.0 °C? 10,500 joules 12,200 joules 15,300 joules 18,200 joules

elf-contained self-rescue breathing devices convert CO2 into O2 according to the following reaction: 4KO2 (s) + 2CO2 (g) → 2K2CO3 (s) + 3O2 (g) How many grams of KO2 are needed to produce 100.0 L of O2 at 20.0 °C and 1.00 atm?

A radioactive element of mass 20.0g was isolated and stored. It was discovered after 40days that 2.5g of the element remained undecayed. Calculate the half life of the element.

If a 53.27g sample of potassium nitrate (KNO3) is dissolved in enough water to make 461 mL of solution, what will be the molarity?

What is the ratio of carbon, hydrogen, and oxygen in most carbohydrates?

Which part of Dalton's atomic theory was disproved by Thomson's experiment? O Atoms cannot be created, destroyed, or divided into smaller particles. O Chemical reactions occur when atoms combine, separate, or rearrange.

Of the following, which is most likely to result after a farmer sprays his crops with pesticides? A. The crops die. B. The insect population increases. C. The soil dries up and blows away. D. A neighbor's well tests positive for pesticides.

How many liters does the following number of atoms of helium take up? 9.42x10^22 atoms He

Why isn't biuret reagent required for determining the absorption spectrum of hemoglobin?

During which phase change does the arrangement of water molecules become more orderly A.) melting B.) subliming C.) boiling D.) condensing