This is how carbon looks on a revised periodic table that uses intervals for the standard atomic weights of some elements. Standard atomic weights, those numbers emblazoned under the elements on the ...

If you've learned all the elements from actinium to zirconium, it's time to head back to the periodic table, where there's a new, extremely heavy element in town. In case you forgot your high school ...

For example, the atomic number of chlorine is 17. Every chlorine atom has 17 protons and 17 electrons. It has 17 positive charges and 17 negative charges, meaning that it is neutral overall. Atoms of ...

Standard atomic weights, those numbers emblazoned under the elements on the periodic table, were once thought of as unchanging constants of nature. But researchers have tweaked the atomic weights of ...