- Physical Sciences
a group of elements that are non-reactive, monatomic gases (Group 0, 8 or 18).
a zigzag, stepped line on the periodic table that separates the metals from the non-metals.
a crystal lattice of positive kernels in a sea of delocalised electrons to which they are...
the sum of the number of protons and neutrons (the nucleons) in the nucleus of an atom. It...