A certain atom has an energy state 3.50 eV above the ground state. When excited to this state, the atom remains for 2.0 ms, on average, before it emits a photon and returns to the ground state. (a) What are the energy and wavelength of the photon

Idon't really understand this can you me and show your work.☺☺[ chemistry b] subject [ electron transfer in lonic bonds]grade( 12)

Given the following equation: 2a1 + 3mgcl2 --> 2alcl3 + 3mg how many moles of aluminum chloride are produced from 2.5 moles of magnesium chloride?

Calculate the estimated density of each ball. use the formula d = m/v where d is the density, m is the mass, and v is the volume. record your calculations in table a of your student guide. given that the density of water is 1.0 g/cm3, make a prediction about whether each ball will float in water. record your prediction in table a. what is the estimated density of the table tennis ball? record your answer to the nearest hundredth