When two or more atoms of the same element bond, a(n) (Click to select) is formed; this portion of a compound is the smallest part that retains the properties of the compound. When two or more different elements bond together in a fixed ratio, a(n) (Click to select) is formed. Water is an example of a(n) (Click to select) because it is a combination of hydrogen and oxygen atoms, and two hydrogen atoms bonded to one oxygen atom retain the properties of water. All atoms contain negatively charged (Click to select) that orbit around a positively charged nucleus. This nucleus contains positively charged (Click to select) and neutrally charged (Click to select) . It is the negatively charged (Click to select) that give atoms properties that are favorable in forming chemical bonds.