Sodium reacts with chlorine gas to form sodium chloride. 2Na + Cl2 → 2NaCl What mass of chlorine gas will react with 92.0 g of sodium?

Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in the n=3 level to an orbital in the n=7 level.

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

How many moles are in 123.0 grams of kclo4?