Helium oxygen carbon fluoride and chlorine are all nonmetals using the periodic table which pair of nonmetals do you predict has the most similar properties and why

Calculate the energy required to ionize a hydrogen atom to an excited state where the electron is initially in the n = 5 energy level. report your answer in kilojoules

Find the mass, in grams, of 5.00*10^23 molecules of f2

6) (a) calculate the absorbance of the solution if its concentration is 0.0278 m and its molar extinction coefficient is 35.9 l/(mol cm). the depth of the cell is 5 mm. (b) what is the %t? (7) calculate the absorbance of the solution if the transmitted light intensity is 70% of the initial light beam intensity