Open Question
Why does the lightest halogen, which is also the most chemically reactive, exhibit a decrease in reactivity as you move down the column of halogens in the periodic table? Explain this trend in terms of periodic properties.
You have cracked a secret code that uses elemental symbols to spell words. The code uses numbers to designate the elemental symbols. Each number is the sum of the atomic number and the highest principal quantum number of the highest occupied orbital of the element whose symbol is to be used. The message may be written forward or backward. Decode the following messages: a. 10, 12, 58, 11, 7, 44, 63, 66
Use Coulomb's law to calculate the ionization energy in kJ>mol of an atom composed of a proton and an electron separated by 100.00 pm. What wavelength of light has sufficient energy to ionize the atom?