Unit+2+-+Atoms,+Molecules+&+Ions

__**Molecule**__ - an aggregate of a few atoms that are the fundamental building blocks in all gases, solids, and many liquids; held together by covelant bonds
 * __Atom__** - the smallest particle of an element

**__Ions__** - charged particles that forms when an atoms loses or gains electrons google images

**__3 Main Postulates of Modern Atomic Theory__** []
 * 1) An element is composed of tiny particles called atoms.
 * 2) In an ordinary chemical reaction, atoms from one substance to another, but no atom of an element disappears or is changed into an atom of another element.
 * 3) Compunds are formed when atoms of two or more elements combine.

**__3 Basic Laws of Chemistry__** __//Law of Conservation of Mass//__ - There is no change in mass in a chemical reaction. [] //__Law of Constant Compostion__// -A compound ALWAYS contains the same elements in the same proportions by mass.

//__Law of Multiple Proportions__// - The masses of one element that combine with a fixed mass of the second element are in a ratio of small whole numbers. [] of the atom ||
 * **Particle** || **Relative Mass** || ** Relative Charge ** || **Location** ||
 * **Proton** || 1.00728amu || +1 || nucleus ||
 * **Neutron** || 1.00867amu || 0 || nucleus ||
 * **Electron** || 0.00055amu || -1 || outer regions

Atomic Number- ﻿The number of protons and electrons in a nucleus for a certain element in a neutral atom. Mass Number - Number of protons plus the number of neutrons in the nucleus.

Isotopes - Atoms that contain the same number of protons but a different number of neutrons.



**of Protons** || **Number of Neutrons** || **Atomic Number** || **Mass Number** || **Nuclear** **Symbol** || 6 || 6 ||
 * **Atom** || **Number**
 * Carbon-12 || 6 || 6 || 6 || 12 || 12 C
 * Carbon-14 || 6 || 8 || 6 || 14 || 14 C

__Radioactivity-__ ﻿ Unstable isotopes decomposing, nuclear transformation.

__A stable nuetron-protron ratio //**INCREASES**// with atomic number.__

**__3 Forms of Radiation__** 1. Beta ( β) - identical in their proporties to electrons 2. Alpha ( α) - He nuclei carrying a +2 charge 3. Gamma Rays ( ƴ) - consist of high energy radiation; NOT a particle

__Molecular Formula__ - The number of atoms of each element is indicated by a subscript written after the symbol of the element. H2O, NH3, CH4 __Structural Formula__ - Shows bonding pattern within the molecule. __Condensed Structural Formula__ - Suggests the bonding pattern in the molecule and highlights the presence of a reactive group of atoms within the molecule.

CH3OH, CH3NH2


 * ALL IMAGES FROM GOOGLE IMAGES. :)