A sample that weighs 107.75 g is a mixture of 30% helium atoms and 70% krypton atoms. How many particles are present in the sample?

Why is the half life of a radioactive substance independent of the initial amount of the substance that is present

3.) Why was the crucible placed in a drying oven overnight?

Does the mass of water increase or decrease when it changes to ice

Some species are no longer living but we know they existed one time. we know this because ...

The density of solid W is 19.3 g/cm3. How many atoms are present per cubic centimeter of W?

Actions of the non-valence electrons, diluting the force of the attraction between nucleus and valence electrons is called

Which statements accurately describe the greenhouse effect? Check all that apply. It is caused by liquids on Earth's surface. It is caused by gases in Earth's atmosphere. It warms up Earth's surface and the lower atmosphere.

How is geothermal produced

B2O3 (s) + 3C (s) + 3Cl2 (g) - - - > 2 BCl3 (g) + 3CO (g) Calculate how many moles of BCl3 are produced from the reaction of 61.0g of B203? A. 1.75 mol B. 0.0150 mol C. 51.3 mol D. 211 mol

A gas has a volume of 10 L at 0 C what is the final temperature of the gas if it volume increases to 25L