200cm3 of oxygen diffuse through a porous partition in 10 seconds. How long will it take 120cm3 of chlorine to diffuse through the same partition under the same condition of temperature and pressure.

A 20g piece of lead absorbs 566 joules of heat and its temperature changes from 35 oC to 195 oC. Calculate the specific heat. 40g of water is heat at 40 oC and the temperature rise to 75 oC.

Which statement is true about the atomic mass? A. It can be greater than the atomic number B. It is never greater than the atomic number C. It always equals the atomic number D. It is always lower than the atomic number

If an element has three isotopes with known masses, what other information is needed to find the average atomic mass of the element

How many moles in 1.5*10^23 molecules of NH3?

Which layer of the atmosphere has the least amount of ultraviolet rays from the sun?

The density of a substance with a mass of 48 grams and a volume of 3 ml is what

An atom of beryllium (m = 8.00 u) splits into two atoms of helium (m = 4.00 u) with the release of 92.2 kev of energy. if the original beryllium atom is at rest, find the kinetic energies and speeds of the two helium atoms

The most penetrating neclear radiation is

Certain object has a mass of 60 g and a volume of 32.6 cm³ what type of objects is the density

Which of the following statements is true? A. A producer usually obtains food by hunting other organisms. B. Humans that prepare their own meals are producers. C. A producer must be a plant. D. Consumers depend upon producers for food.