The chemical properties of chlorine (ci) are most similar to the chemical properties of which element ?
a) sulfur (s)
b) bromine (br)
c) selenium (se)
d) argon (ar)

Flourine is found to undergo 10% radioactivity decay in 366 minutes determine its halflife

Using data from seismic waves, geologists have learned that earth’s interior is made up of several

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