GEL 2 Lecture Notes - Lecture 3: Valence Electron, Atomic Number, Electron Configuration
Document Summary
The rocks occur as aggregates of several kinds of mineral. Aggregate: implies that minerals are joined in such a way that the properties of each mineral are retained. Elements: a substance that cannot be broken down into simpler substances by chemical or physical means. Periodic table: the arrangement of elements in rows so that those with the similar properties are in the same column. Chemical compounds: when many elements join together with atoms of 1 or more other elements and form together. Atom: the smallest particle of matter that retains the essential characteristics of an element. The central region of an atom is the nucleus. The nucleus contains protons (which are dense particles with a positive electrical charge) and neutrons (have the same mass as a proton, but don t have an electrical charge. Orbiting the nucleus are electrons (which have a negative electrical charge)
