Is helium is lightest monatomic element chemical properties

Which of the following can lead to groundwater shortages? a. pollution b. use exceeding the rate of replenishment c. lack of precipitation d. all of the above

Which of the following choices represents hydrogen peroxide A. hydrogen atom B. a molecule C. a oxygen atom D. diatomic oxygen

What happens during midwinter when the North Pole is tilted away from the Sun? A) There is no night. B) The days are very long. C) The days are very short. D) There is no sun at all.

How many molecules of glycerol (c3h8o3; molecular mass = 92) are present in 1 l of a 0.5 m glycerol solution?

sugar dissolving in water was a good example of what kind of change? A. physical B. chemical C. Electical

How much heat is needed to raise the temperature of 75 g of a substance by 15 C when the specific heat is 0.92 J/g-C?

A nitric acid solution flows at a constant rate of 5L/min into a large tank that initially held 200L of a 0.5% nitric acid solution. The solution inside the tank is kept well stirred and flows out of the tank at a rate of 10L/min.

How many molecules are in 237g (about a cup of water)

3. A compound was analyzed and found to contain 9.8 g of nitrogen, 0.70 g of hydrogen, and 33.6 g of oxygen. What is the empirical formula of the compound?

A 126-gram sample of titanium metal is heated from 20.0°C to 45.4°C while absorbing 1.68 kJ of heat. What is the specific heat of titanium?