A laser beam has a wavelength of 500nm and the power of the laser beam is 2.8W. The number of emitted photons by this laser during time t is 3.6×10^18 photons. Calculate the time t. (1W = 1 J/s)

What happens to isotopes that are unstable?

How many moles are in 123.0 grams of kclo4?

The lattice enthalpy (formation of ionic solid from ions in the gas phase) for agcl(s) is -916 kj/mol and the hydration enthalpy (dissolution of gaseous ions into water) is -850 kj/mol. how much heat (in joules) is involved in forming 1l of saturated agcl solution (1.8 × 10-4 g / 100 ml water) by dissolving agcl(s)? assume solution volume does not change much upon dissolution. the equations are given below. ag+(g) + cl−(g) æ agcl(s)