If a human eye receives a 1.45 x 10^-17 J signal from photons whose wavelength is 550nm, how many photons have hit the eye?

The pressure inside a hydrogen-filled container was 2.10 atm at 21 ? c. what would the pressure be if the container was heated to 92 ? c ?

Butane gas reacts with oxygen gas to give carbon dioxide gas and water vapor (gas). if you mix butane and oxygen in the correct stoichiometric ratio, and if the total pressure of the mixture is 390 mmhg, what is the pressure (in mmhg) of water vapor after the reaction is completed (temperature and volume do not change).

Which best describes the activation energy of a chemical reaction? a. the combined energy of all the reactants b. the amount of energy required for a reaction to occur c. the difference in energy between products and reactants d. the potential energy stored in the bonds of reactants and products