Links to Chemistry information:
Chemical Change vs. Physical Change.
Atoms, Elements and Isoptopes.
The Mole and Alvagodro Number.
Stoichiometry Practice Problems.
Misc. Notes
When an atom of an element that ends in "ine" becomes an ion, its ending becomes "ide".
At the top of the periodic table, you'll see that some columns are labeled 1A, 2A, 3A, 4A, 5A, 6A, 7A, and 8A. The atoms making up the elements in those columns have corresponding numbers of valence electrons. For example, all of the elements in the column labeled 1A have one valance electron, all of the elements in column 5A have five valence electrons, and all of the elements in the 8A column (except for helium) have eight valence electrons.
Think about giving insulin to a patient with diabetes—a disorder that causes problems with a person's blood sugar levels. Insulin binds with molecules in a cell's membrane, causing the membrane to let sugar that's present in the blood move into the cell. If the insulin dosage is too low, the blood sugar levels will continue to be dangerously high because not enough sugar can leave the blood and enter the cells. This leads to a condition called hyperglycemia. If the insulin dosage is too high, too much sugar will leave the blood, and blood sugar levels will drop dangerously low. Now the patient will suffer from hypoglycemia.
The water-soluble vitamins include vitamin C and the eight B vitamins (biotin, folic acid, niacin, pantothenic acid, riboflavin, thiamine, vitamin B , and vitamin B ). Because these vitamins are watersoluble, your body doesn't store them. Instead, your body sends most of the excess amounts of these vitamins out in your urine. That's why your urine looks more yellow if you take a multi-vitamin or extra vitamin C. Very high amounts of water-soluble vitam
The fat-soluble vitamins include vitamins A, D, E, and K . These vitamins dissolve in your fat tissues and don't leave your body in your urine. While you shouldn't take large doses of any vitamin (unless prescribed by your doctor), excessive amounts of fat-soluble vitamins can definitely cause you harm. Excessive amounts of vitamin D, for example, can cause your bones to release too much calcium in your blood, which can damage your bones, heart, and kidneys.
These are just a few of the many examples of colloids, both man-made and naturally occuring. Aerosols: Man-made: Aerosol sprays, insecticide spray, smog. Natural: Fog, clouds. Solid aerosol: Natural: Smoke, dust. Foam: Man-made: Shaving lather, whipped cream. Emulsions: Man-made: Mayonnaise, cosmetic lotion, lubricants. Natural: Milk. Sols: Man-made: Paint, ink, detergents, rubber (a latex - also occur naturally). Solid foams: Man-made: Marshmallow, styrofoam, insulation, cushioning. Gels: Man-made: Butter, jelly. Solid sols: Man-made: Certain alloys. Natural: Pearl, opal. Biological macromolecules and cells may be considered to be biocolloids and many foods are also colloidal in nature. Colloids are also an important feature of the natural environment.
Water doesn't break apart sugar molecules because water molecules are polar and sugar molecules are nonpolar. Sodium chloride molecules are polar, though, so a solution of water and sodium chloride will conduct electricity.
Acids are chemicals that break apart in water to release hydrogen ions (H+). Hydrogen ions are highly reactive and can cause severe tissue damage if their concentration is too high because they mess up the structure of proteins. That's why contact with strong acids causes such terrible burns. Still, you need some hydrogen ions in your body's fluids because they're necessary for many of your body's chemical reactions. Strong acids release almost all of their hydrogen ions in water. Weak acids, however, don't easily break apart in water.
Bases release ions, such as hydroxide ions (OH-), which then combine with hydrogen ions. While acids taste sour, bases taste bitter. Just like acids, strong bases easily break apart in water and weak bases don't. The bases in egg whites, for example, are weak, while many household cleaning products contain sodium hydroxide (NaOH)—a very strong base. Strong bases can also badly injure tissues. That's why you should always keep cleaning agents out of the reach of children.
High blood pressure - There's a saying that I teach my anatomy students and that's this: "Where sodium goes, water follows." So, if you have excessive amounts of sodium in your blood, water will move from the surrounding tissues into the blood as well. This increases the volume of liquid you have in your blood vessels, which increases the pressure on the blood vessel walls.
Testing pH of Common Household Substances. This activity will allow you to test household substances to see if they're acidic or basic. You'll use an indicator that will change color when exposed to a solution with a pH less or more than 7. Use pure cranberry juice for your pH indicator. You can also cut a few leaves of red cabbage into small pieces and boil them for 5 minutes to create a liquid that will work as an indicator as well. Take several clear glasses and add approximately 1 inch of indicator solution to each glass. Add a different household solution to each glass. Label each glass with tape and marker so you know what substance is in each one. I suggest using the following: vinegar, lemon juice, milk, shampoo, window cleaner, and detergent. You can also make solutions of water and baking soda, aspirin, and antacids to check the pH of those substances. Be very careful to protect children from any of the solutions that could hurt them and avoid getting anything poisonous in your eyes, mouth, or nose. Stir and observe how the color of the solution changes. Red, pink, and lavender colors indicate the presence of an acid. Blue, green, and yellow colors indicate the presence of a base. A red color indicates a strong acid, and a yellow or yellowish green color indicates a strong base. A purple color indicates that a solution is close to neutral. Record your results. Add some vinegar to one of your basic solutions and see if you can bring the pH back to neutral. If you try other combinations, make sure you do not mix anything with bleach and ammonia together because you could end up with some very dangerous fumes.
Chemistry Glossary
Activation Energy - minimum amount of energy required to start a chemical reaction.
Anion - an ion with a negative charge (an extra electron).
Antioxidant - bind with unstable chemicals called free radicals . Free radicals damage other compounds in your body by stealing one of their electrons. Vitamins that act as antioxidants (primarily vitamins C and E) donate one of their electrons to the free radicals, keeping them from damaging other compounds.
Atom - smallest complete unit of matter.
Atomic Mass - an average mass for the isotopes of the element in a typical sample of many atoms of that element.
Atomic Number - (symbol "Z") how many protons are in each atom of an element. It tells you how many electrons are in each atom of an element as well, because the number of protons and electrons are the same in a complete atom.
Bio-organic molecules - molecules that make up the structures of living organisms, as well as many of the chemicals that living organisms produce. Bio-organic molecules include carbohydrates, lipids, proteins, and nucleic acids.
Buffers - reduce the effects of strong acids by reducing the amount of hydrogen ions that are free to wreak havoc with other chemicals.
Chemical Properties - the way an element or compound changes to an entirely differnt substance under certain circumstances.
Calorie = 1 Cal = 1000 kcal = 4,184 J
Catalyst - are chemicals that speed a chemical reaction up by lowering the activation energy, but they aren't changed themselves in the chemical reaction.
Cation - an ion with a positive charge (missing one electron).
Chemistry - involves the study of matter and energy.
Coefficient - the "2" at the left in "2H", meaning 2 hydrogen atoms.
Cofactors and coenzymes - help enzymes carry out their individual functions. For example, the B vitamin called biotin helps enzymes catalyze chemical reactions that result in the formation of fatty acids.
Colligative properties - physical properties that depend on the concentration of a solute in a solvent. In other words, they depend on the number of particles in solution rather than the chemical composition of the solution.
Collision Theory - atoms and molecules only react if certain conditions are met. These conditions include the following: (A) The reactants must collide. (B) When the reactants collide, they must have the proper orientation for the reaction to occur. In other words, they must hit each other at just the right angle or the reaction won't take place. (C) When the reactants collide, they must do so with sufficient energy to break or form chemical bonds. It takes a small amount of energy to break or form a weak bond, and it takes a large amount of energy to break or form a strong bond.
Combustion - When chemicals react with oxygen to create an explosion.
Compound - a substance made up of atoms from two or more elements. Compounds can't be broken down into simpler substances by physical means (heating, filtering, stirring, evaporating), but they can be broken down into simpler substances by chemical means.
Concentration of a solution - how much solute is dissolved in a solution. Here are four ways you can describe a solution's concentration: (A)Mass-mass percent (percent by mass), (B) Volume-volume percent (percent by volume), (C) Mass-volume percent, and (D) Molarity
Conservation of mass - The law of conservation of mass tells us that we must have the same number of atoms of each element on both sides of the equation.
Covalent Bond - when atoms achieve a stable valence shell by sharing electrons with other atoms (for example, water). Also known as a true covalent bond.
Decomposition reactions - In these reactions, a larger molecule (the reactant) breaks apart to become smaller molecules (the products).
Density - mass divided by volume - g/cubic cm (= 1 milliliter or grams/milliliter)
Distillation - Simple - Simple distillation is a method for separating the solvent from a solution. For example, water can be separated from salt solution by simple distillation. This method works because water has a much lower boiling point than salt. When the solution is heated, the water evaporates. It is then cooled and condensed into a separate container. The salt does not evaporate and so it stays behind.
Distillation - Fractional - is a method for separating a liquid from a mixture of two or more liquids. For example, liquid ethanol can be separated from a mixture of ethanol and water by fractional distillation. This method works because the liquids in the mixture have different boiling points. When the mixture is heated, one liquid evaporates before the other.
Double-replacement reactions - This type of reaction involves two molecules of compounds on the reactant side of the equation, which exchange parts of the molecules with each other and form two entirely different molecules. AB + CD ☛ AD + CB
Electrolyte - a compound formed by the attraction of ions. Salt and hydrochloric acid are electrolytes. Electrolytes contain particles that are held together by ionic bonds or easily broken polar covalent bonds, and these bonds are relatively weak. Because electrolytes contain weak bonds, water can break them apart. When the bonds holding the particles of an electrolyte break apart, ions result. Scientists sometimes say that electrolytes dissociate in water, or they may say that electrolytes ionize in water.
Electronegativity - refers to how badly an atom wants to attract the valence electrons of other atoms. Generally, an atom of a nonmetal has a higher electronegativity value than an atom of a metal. Also, as you move to the right on the periodic table, the electronegativity of atoms increases. (This isn't true for the noble gases—they don't naturally form chemical bonds, so they have an electronegativity value of 0.0.) As you move down the periodic table, though, electronegativity of atoms decreases. That's because the nuclei of larger atoms are farthest away from their valence electrons.
Element - a substance that is made up of only one kind of atom.
Endothermic Reaction - in which the products absorb some of the activation energy.
Energy - the ability of a substance to perform work or produce heat.
Enzyme - a biological catalyst. Most enzymes are protein molecues.
Evaporation - used to separate a soluble solid from a liquid. For example, copper sulfate is soluble in water – its crystals dissolve in water to form copper sulfate solution. During evaporation, the water evaporates away leaving solid copper sulfate crystals behind.
Exothermic Reation - In which energy is released.
Filtration - a method for separating an insoluble solid from a liquid. When a mixture of sand and water is filtered: the sand stays behind in the filter paper (it becomes the residue) the water passes through the filter paper (it becomes the filtrate)
Ionic Bonds - a bond created when two ions attract each other (such as salt). Bonds between metals and nonmetals are typically ionic bonds, while bonds between two nonmetals are typically covalent bonds.
Isomers — compounds that have an identical molecular formula but a different arrangement of atoms.
Isotope - atoms of an element that have different numbers of neutrons.
Joule -
Kenetic Energy - energy in motion.
Law of Conservation of Mass. This law says that atoms are neither created nor destroyed (except in nuclear reactions). So, the mass of the reactants and the products must equal each other. They stay the same because you don't lose or gain any atoms.
Mass - measures how many particles exist in a solid, liquid or gas. (Not weight)
Mass Number - (symbol "A") the number of protons plus the number of neutrons.
Matter - anything that has mass (contains particles) and takes up space.
Mixtures - contain two or more pure substances that you can separate by physical means such as heating or evaporation. Each of its substances retains its own chemical identity, and their concentration can vary. Mixtures may be homogeneous or heterogeneous. Homogeneous mixtures contain particles that have the same properties throughout the mixture. In other words, no matter where you take a sample from a homogeneous mixture, it will have the same percentage of different pure substances. Solutions contain very small particles that are dissolved in another substance. Colloids contain particles with materials that disperse rather than dissolve. Heterogeneous mixtures, on the other hand, contain areas with visibly different compositions. A heterogeneous mixture with large particles that eventually drop to the bottom of a container a suspension.
Mole - 6.02 x 10²³. Scientists call this number Avogadro's number. The mass of a mole of any element or compound (its molar mass) is the same number in grams as its atomic mass.
Molecule - one particle of a compound.
Nucleon - particle in the nucleus - i.e. Proton or Neutron.
Nucleus - center of an atom.
Organic compound - contains both carbon and hydrogen atoms.
Paper chromatography - a method for separating dissolved substances from one another. It is often used when the dissolved substances are coloured, such as inks, food colourings and plant dyes. It works because some of the coloured substances dissolve in the solvent used better than others, so they travel further up the paper.
pH scale - measures the concentration of hydrogen ions in a substance, a measure of acidity. Like many variables in your body, your pH must stay within a narrow range. If your pH gets too low (acidic), your body will take steps to raise it. If it gets too high (alkaline), your body will take steps to lower it. Distilled water has a concentration of hydrogen ions of just 0.0000001 grams per liter. Distilled water has a pH of 7. Every change in whole numbers represents a ten-fold increase or decrease in acidity.
Physical Properties - those that can be observed or measured without changing its composition.
Polar covalent bonds - when two atoms with significantly different electronegativity values share electrons, a polar covalent bond forms. This means that the electrons aren't shared equally. They're attracted more strongly to the atom that is more electronegative.
Polyatomic ion - a group of atoms that has an electrical charge.
Potential Energy - stored energy.
Precipitate - a solid substance in a liquid.
Rotational Motion -
Single-replacement reaction - an atom or molecule on the reactant side replaces one of the other atoms or molecules to form an element and a new compound.
Specific Gravity - the density of a substance divided by the density of water at 4°.
Specific Heat - amount of heat needed to raise one gram of a substance exatly 1C.
Surface Tension - the particles on the surface of a liquid have a stronger attraction to each other than particles below the surface
Synthesis reaction - a chemical reaction in which small molecules come together to form larger molecules. Both the formation of hydrogen molecules and the formation of water molecules are synthesis reactions.
Thermal energy - heat - moves from hot to cold.
Thermal equalization -
Universal solvent - H2O because it dissolves so many substances for two reasons. First, it's a polar molecule, which means the atoms in the molecule have slight charges to them. Second, the hydrogen bonds between molecules of water are very weak. This means that water molecules can move apart and allow other molecules to slip between them.
Transitional Motion - when atoms or molecules move in a straight line.
Valence Electrons - electrons in the outermost energy level of the atom.
Vibrational Motion -
Vitamins - organic compounds that your body requires in small amounts for many different chemical reactions. (An organic compound contains both carbon and hydrogen atoms.
States of Matter
| Term | Solid | Liquid | Gas |
|---|---|---|---|
| Shape | Holds its own shape without a container. | Fills the bottom of a container. | Fills entire container and will try to escape. |
| Volume | Definite - hard to compress or expand | Definite - hard to compress or expand | Indefinite - can be expanded or compressed. |
| Structure | Particles packed tightly together. | Packed - but not tightly | Particles are very far apart |
| Movement of Particles | Vibrate or Spin | Can move around each other | Move at high speeds in all directions |
| Attraction between molecules | Intermolecular particles | Cohesive forces | None |
| Energy Levels | Low | Medium | High |
Changing States of Matter
| Term | Definition | Role of Energy |
|---|---|---|
| Melting | Solid to Liquid | Energy added |
| Vaporization | Liquid to Gas | Energy added |
| Sublimation | Solid to Gas | Energy added |
| Condensation | Gas to Liquid | Energy removed |
| Freezing | Liquid to Solid | Energy removed |
| Deposition | Gas to Solid | Energy removed |
Temperature Scales
| Characteristics | Fahrenheit | Celsius | Kelvin |
|---|---|---|---|
| Absolute zero | -460° | -273° | 0° |
| Freezing Point of Water | 32° | 0° | 273.15° |
| Boiling Point of Water | 212° | 100° | 373.15° |
| F=1.8c+32 | C=(F-32)/1.8 |
Metric Prefixes
| Prefix | Symbol | Description |
|---|---|---|
| Giga | G | One billion times the base unit |
| Mega | M | One million times the base unit |
| kilo | k | One thousand times the base unit |
| deci | d | One tenth of the base unit |
| centi | c | One hundreth of the base unit |
| milli | m | One thousandth of the base unit |
| micro | Greek Mu | One millionth of the base unit |
Common Conversions
| Dimension | Example | Example |
|---|---|---|
| Volume | 946 ml = 1 quart | 1 liter = 1.06 quarts |
| Length | 2.54 cm = 1 inch | 1 m = 39.4 inches |
| Length | 1 km = .621 miles | |
| mass | 1 kg = 2.2 pounds (on earth) | 454 g = 1 pound (on earth) |
Periodic Table Groups
| Metals | Characteristics |
|---|---|
| Good conductors of electricity. | Poor conductors of electricity. |
| conductors of heat. | Poor conductors of heat. |
| Ductile (can be drawn into wires). | non-ductile. |
| Malleable (Can be hammered flat) | Non-malleable |
| Solid at room temp. (except mercury) | Solid, liquid or gas at room temperature |
| Metallic silver or gray (except gold and silver) | Non-metalic luster |
Periodic Table Groups
| Group | Characteristics |
|---|---|
| 1A - Alkali Metals | React very readily with water and other elements. Soft and shiny. Ductile and maleable. |
| 2A - Alkali Earth Metals | React more slowly than Alkali. Also soft and shiny. Ductile and maleable. |
| B - Transition Metals | Ductile and maleable. |
| Malleable (Can be hammered flat) | Non-malleable |
| Solid at room temp. (except mercury) | Solid, liquid or gas at room temperature |
| Metallic silver or gray (except gold and silver) | Non-metalic luster |