Some scientists believe that helium should not be used to inflate party balloons. why

MgO (s) + H2O (l) → Mg (OH) 2 (aq)

Lead is an important input in the production of crystal. If the price of lead decreases, then we would expect the supply of a. crystal to be unaffected. b. lead to increase. c. crystal to decrease. d. crystal to increase.

A standard solution is prepared for the analysis of fluoxymesterone (C20H29FO3), an anabolic steroid. A stock solution is first prepared by dissolving 10.0 mg of fluoxymesterone in enough water to give a total volume of 500.0 mL. A 10.

Calculate the wavelength, in nanometers, of the spectral line produced when an electron in a hydrogen atom undergoes the transition from the energy level n = 5 to the level n = 2.

Scientific theories are always. a theory may be changed as a result of?

Hemoglobin, a protein in red blood cells, carries o2 from the lungs to the body's cells. iron (as ferrous ion, fe2+) makes up 0.33 mass % of hemoglobin. if the molar mass of hemoglobin is 6.8 Ã 104 g/mol, how many fe2 + ions are in one molecule?

What could you predict about a methane molecule that would most likely be made by using both the quantum model of the atom and John Dalton's model?

What is the molar mass of an unknown hydrocarbon whose density is measured to be 1.97 g/l at stp?

Which is an example of flow of heat through conduction

Which of the following is an extensive physical property of matter? volume viscosity odor density