Responses (1)
This is simple arithmetic. You need to be perfectly prepared in arithmetic to do well in chemistry. So get into your book and learn the process, then practice with numbers until you can do these things in your head.
You do have a printed periodic table, right? You can get the information at www.chemicalelements.com/index.html but you really need your own printed copy to carry with you. It will be a primary reference for everything you do.
There is a diagonal line, B-C, Si-P, Ge-As, Sb-Te, and Po-At. Elements to the left of the line are metals, meaning they lose an electron easily, elements to the right of the line are non-metals, and elements on the line are semiconductors.