Turbo TAKS Week 4 Lesson 1: Matter Lesson 2: Density Lesson 3: Periodic Table Lesson 4: Chemical Formulas

All matter can be classified into one of three areas: 1. Elements 2. Compounds 3. Mixtures Elements:Elements are the basic chemical structures that cannot be broken down. Examples: I-Iodine Na-Sodium Co-Cobalt C-Carbon

Compounds:are formed when two or more atoms chemically combine. They cannot be separated by physical means. Examples: NaCl-Salt CO 2 - Carbon dioxide

Mixtures: are formed when two or more substances are mixed together but, they are not chemically combined. Mixtures can easily be separated by a physical means. (Distillation, using a magnet, dissolving one in water – then letting the water evaporate.) Heterogeneous Mixture:Mixtures that are not the same throughout-Ex. Pizza, Salad If you take multiple samples of it, they may look different from each other! Homogeneous Mixture: A Mixture that is the same throughout-Ex. Kool-Aid, Brass

Physical/Chemical Changes: Physical Changes in matter that do not affect the chemical composition of the material. They often alter the volume, shape, or texture of the material, but it is often possible to “undo” a physical change and return the material to its formal condition. Ex. Phase changes (melting, freezing,etc) Chemical Changes in matter do ALTER the chemical composition of the material. Ex. Producing a gas, heat change, color change Wood burns into ash and smoke.Stomach acid digests your food. Metals rust (oxidation)

Lesson 2: Density, Viscosity, Buoyancy

DENSITY Density is the ratio of mass to volume and can be calculated by dividing the mass by the volume. Whether your sample is cut in half, quarters, or little bitsy pieces, the density REMAINS THE SAME! * Denser liquids will sink under less dense ones. Liquids mixed in a container will separate into a column of distinct layers. D = mass/volume Common units of density include: g/mL, g/cm 3

BOUYANCY If you place an object in a liquid like water, the water will push upward with a buoyant force equal to the weight of the water displaced by the object. If the average weight of the object is less than the weight of the displaced water, the object will float. This buoyancy explains why ships that weigh thousands of tons are able to float on the ocean. If a material floats in water (buoyant) than its density is less than 1g/mL- if it sinks, it’s greater than 1 g/mL.

VISCOSITY A measure of how much fluid resists flowing. High density = High viscosity Depends on temperature –Viscosity decreases as temperature increases. Low viscosity = water High viscosity = syrup or oil

Lesson 1 Law of Conservation of Mass Balancing Equations

Law of Conservation of Mass During chemical changes, matter cannot be created or destroyed, but only converted from one form to another. Substances in chemical reactions may change their properties or number, but the total amount of matter must remain the same. The observation is known as the Law of Conservation of Mass. The total mass of substances does not change during a chemical reaction.

According to the law of conservation of mass, how much zinc was present in the zinc carbonate?

Balancing Chemical Equations 1. Write down the number of each of the atoms found Left side = reactants Right side = products 2. Begin to balance Let’s try…. __ Mg (g) + _ NH3 (g)  __ H2 (g) + __Mg3N2 (s) RP

_3_ Mg (g) + _2_ NH3 (g)  _3_ H2 (g) + __Mg3N2 (s) ReactantsProducts Mg- 1 3 N- 1 2 H- 3 6 Mg- 3 N- 2 H- 2 6 BALANCED!!!