How many moles of helium atoms are there in 2.4 x 10^24? need equation

What are the elements in the "dip" of the periodic table called? Transition Metals Pure Elements Gases Non Metals

Calculate the theoretical yield of hydrogen gas (in L) at 295 K for a reaction of 1.50 g magnesium with excess hydrochloric acid. If 1.205 L of gas is produced, what is the percent yield of the reaction?

A tank contains 200 L of fluid in which 30 grams of salt are dissolved. Brine containing 1 g of salt per liter is then pumped into the tank at a rate of 4L/min; the well mixed solution is pumped out at the same rate.

why do atmoic numbers increase from left to right across any given row of the periodic table

The solubility of N2 in water at a particular temperature and at a N2 pressure of 1 atm is 6.8 * 10-4 mol L-1. Calculate the concentration of dissolved N2 in water under normal atmospheric conditions where the partial pressure of N2 is 0.78 atm.

5. Identify a suitable method that would be used to separate mixture of the follow [b]Water and ethanol c]Table salt dissolved in water d] iodine and potassium Pul the table below

How much energy is needed to convert 57.3 grams of ice at 0.00°c to water at 75.0°c? specific heat (ice) = 2.10 j/g°c specific heat (water) = 4.18 j/g°c heat of fusion = 333 j/g heat of vaporization = 2258 j/g?

A certain first-order reaction (A→productsA→products) has a rate constant of 9.90*10-3 s-1s-1 at 45 ∘C∘C. How many minutes does it take for the concentration of the reactant, [A][A], to drop to 6.

Assign the oxidation number for (NH4) 3PO4

When gold is melted and formed in a mold to make a piece of jewelry, what type of change is taking place?