Ahelium balloon contains 0.48g of helium. given the molecular weight of helium is 4.0 g/mol, how many moles of helium does it contain?

Inside a flashbulb, oxygen surrounds a thin coil of magnesium. when the flashbulb is set off, a chemical reaction takes place in which magnesium combines with oxygen to form magnesium oxide. which of the chemical equations matches the reaction above? a. mg + o2 mgo2 + energy b. 2mg + o mg2o + energy c. 2mg + o2 2mgo + energy d. mg + o mgo + energy

If a simple machine aduces the strength of a force, what must be increased? the speed of the input force the work the simple machine performs the size of the simple machine the distance over which the force is applied

Which of the following changes will decrease the total amount of gaseous solute able to be dissolved in a liter of liquid water? (2 points) decreasing temperature decreasing pressure decreasing surface area decreasing solute concentration