5) Radium is a radioactive element that decays into radon gas. Its atomic
mass is 226. How many moles in 500.0 grams of radium? *

Enough of a monoprotic weak acid is dissolved in water to produce a 0.0172 m solution. if the ph of the resulting solution is 2.39 at 20 °c, determine the pka for the acid.

What is the formula for calcium iodide

Place the elements below in order of decreasing ionization energy. aluminum(al) chlorine(cl) magnesium (mg) sulfur(s)