Ions Ions: are charged atoms because number of protons don’t equal number of electrons. Ions: are negatively charged when they gain electrons, they are called anions. Ions: are positively charged when they lose electrons, they are called cations

Isotopes Isotopes: Are two or more forms of an element. Isotopes: have the same number of protons Isotopes: have a different number of neutrons & therefore a different mass. Ex. 35Cl & 37Cl 12C & 14C Isotopes: have the same physical & chemical properties, Isotopes: have different nuclear properties. Some isotopes are unstable or radioactive (radioisotopes), which means that the nucleus has a tendency to break apart and eject very high energy particles into its surroundings.

Isotopes Isotopes:. Can be unstable or radioactive Radioisotopes: the nucleus breaks apart ejecting very high energy particles. Some uses of radioisotopes are: diagnose medical problems (thyroid disease, iodine-131) radiation therapy cobalt-60 carbon-14 dating of ancient humans and artifacts smoke detectors contain americium-241 CANDU reactors uranium-235 heavy water deuterium plutonium-241 spent fuel in a light-water power reactor

Lewis Dot Diagrams "electron dot" diagrams elements in a family on the periodic table have the same number of electrons in the outer shell. valence electrons  the electrons that are involved in chemical bonding. To draw a Lewis dot diagram, write the symbol (this represents the nucleus & inner electrons) draw the valence electrons as dots around the symbol. Put the first four dots on each side, then fill in the sides to a maximum of two dots per side. Ex: H Ca O Ne

Chemical Bonding During chemical reactions, electrons are rearranged between atoms resulting in bonds being formed or broken. Generally, electrons are arranged so that their outer energy level is full. (same number of electrons as the closest noble gas). Two types of bonds are generally formed. Ionic bonds  transfer of electrons from a metal to a non-metal. Covalent bonds  sharing of electrons between two or more non-metals.

Lewis Diagrams of Chemical Bonds Ionic Bonds: Example: bond between lithium & oxygen Li O Li → Naming ionic compounds: The metal keeps it’s name The non metal takes the ending ide Example: NaCl sodium chloride MgF2 magnesium fluoride

Lewis Diagrams of Chemical Bonds Covalent Bonds: Example: bond between oxygen & oxygen O O → (this is a diatomic gas) O=O oxygen gas makes a double covalent bond

Complete the following: compound Number of types of elements Total number of elements Type of Bond Lewis Diagram NaCl Mg F2 O2 CuSO4

Atoms & Their Electrons http://documentaries-plus.blogspot.ca/2011/01/atoms-and-their-electrons.html 34min https://www.youtube.com/watch?v=G9K6PMGt4LM (How O, N & C bond 20 min) The science of snowflakes http://ed.ted.com/lessons/the-science-of-snowflakes-marusa-bradac (4.5 min)