The range for em radiation should be a range of 50 yards hope this help's. <span />
I know what you're asking but I don't think the question is stated properly. Technically, an atom will not join with an "oxide" ion; i.e., the oxide ion is an atom of oxygen to which two electrons have been added. An oxide ion will add to 2 K ions or 1 Ca ion. The K ion has lost just one electron so it takes two of them to equal the 2- charge on the oxide ion whereas the Ca ion has lost two electrons and it takes only one of them to equal the charge on the oxide ion.
Answer: primary colors are those you can't get by mix in other colors. They are red, blue, and yellow. secondary colors come from mixing two primary colors.
