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General Chemistry

General Chemistry. Chemistry. Chemistry is the study of matter and how it changes and interacts with other matter. Matter. MATTER IS THE STUFF AROUND YOU Anything that takes up space or has a mass of any kind is matter.

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General Chemistry

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  1. General Chemistry

  2. Chemistry • Chemistry is the study of matter and how it changes and interacts with other matter

  3. Matter • MATTER IS THE STUFF AROUND YOUAnything that takes up space or has a mass of any kind is matter. • It can have PHYSICAL properties like different densities, melting points, boiling points, freezing points, color or smells. • It can have CHEMICAL properties that define matter. A good example of chemical properties is the way elements combine with each other in reactions.

  4. States of Matter • There are three main STATES of matter. SOLIDS, LIQUIDS, & GASES. • ELEMENTS and compounds can move from one phase to another when special physical forces are present • ex. temperature • Phase describes a PHYSICAL state of matter. If energy is added or taken away, the state of matter is changed. • CHEMICAL FORCES DO NOT CHANGE THE STATE!

  5. What about plastic? • Liquids • What are some characteristics? • Does plastic have any of these characteristics? • Solids • What are some characteristics? • Does plastic have any of these characteristics?

  6. Atoms • The smallest unit of matter having protons, electrons, and neutrons. • Atoms are the basis for everything in the universe • The center is the NUCLEUS. • There are equal numbers of electrons and protons

  7. Periodic Table Click here to print out your own copy of the periodic table.

  8. Periods • Each row is a different PERIODS • All elements in a period have the same number of atomic SHELLS • Every element in the top row (the first period) has one shell for its electrons. • All of the elements in the second row (the second period) have two shells for their electrons. • It continues down the periodic table like that. At this time, the maximum number of shells is seven.

  9. Groups • When a column goes from top to bottom, it's called a GROUP • The elements in a group have the same number of electrons in their outer shell • Every element in the first column (group one) has one electron is its outer shell. • Every element on the second column (group two) has two electrons in the outer shell. • Count the columns and you'll know how many electrons are in the outer shell. • The elements in between, in grey color, are TRANSITION elements. • They have special electron rules.

  10. Exceptions • Hydrogen can have the talents and electrons of two groups, one and seven. • Hydrogen is sometimes missing an electron, and sometimes it has an extra. • Helium can only have two electrons in its outer shell. • It is still grouped with elements that have eight.

  11. Shells • Shells surround the center of an atom. • A shell is sometimes called orbital/energy level. • Electrons live in shells. • Not all shells hold the same number of electrons.

  12. Ions and bonding • A normal atom has a NEUTRAL charge. • has a number of electrons equal to the ATOMIC NUMBER. • ION: a charged atom. Missing or has extra electron(s)

  13. Compounds • When two or more elements come together it is called a COMPOUND

  14. Compounds • No matter what atoms are in a compound, they all want to be "happy". • A happy atom is one with the right number of ELECTRONS in the outer ORBITAL • That desire to be happy is why some elements only combine with a few other elements. Not all elements can make each other "happy".

  15. Ionic/Electrovalent Bonds • ELECTROVALENCE is just another word for something that has given up its electron and become an ion • When they are in the presence of other ions the electrovalent bonds are weaker • Ionic bonds happen when electrons are given up by one atom to another

  16. Covalent Bonds • Covalent compounds happen when the electrons are shared by the atoms

  17. When sodium atoms bond with one oxygen atom there have to be two sodium atoms, each with an extra electron. Each of these Sodium atoms gives oxygen one electron, allowing Oxygen to have a full shell with eight electrons. Is this an example of Ionic or Covalent Bonding?

  18. Combinations • Most compounds are made up of combinations of bonds

  19. Let's use carbon (C) as an example... • There are a lot of carbon (C) atoms in the universe. • The normal ones are called Carbon-12. • Have 6 neutrons. • Odd ones may have 7 or even 8 neutrons • Carbon-14 • Has 8 neutrons (2 extra). • C-14 is considered to be an isotope of the element of Carbon (C). • When C-14 loses the extra neutrons in radioactive DECAY, it will become C-12.

  20. Carbon • All plants have carbon as their most important element. • Every living thing on Earth also needs carbon to survive. • And it needs to be in plants before humans can do anything with it. • Everything that is plastic has carbon in it. • Like gasoline, plastic things are made from oil. • That means carbon is also the most important element plastic.

  21. Reactions • In a reaction, a chemical change must occur. • Turn one compound into another. • It could be ions, molecules, or pure atoms • Single reactions often happen as part of a larger series of reactions. • Take something as simple as moving your arm. The contraction of that muscle needs sugars for energy. Those sugars need metabolized… • A lot has to happen just to perform a simple task!

  22. Catalysts and Inhibitors • Reactions need ACTIVATION ENERGY. A catalyst lowers the amount of energy needed. • Maybe a molecule shifts it's structure. • Maybe two molecules combine and they release energy. • Inhibitors slow the rate of reaction.

  23. Stoichiometry • STOICHIOMETRY is the part of chemistry that studies amounts of substances that are involved in reactions • What do you measure? • Mass of Reactants (chemicals before the reaction) • Mass of Products (chemicals after the reaction) • Chemical Equations • Molecular Weights of Reactants and Products • Formulas of Various Compounds

  24. Stoichiometry Example • You start with two ions and wind up with an ionic compound (NaCl). Na+ + Cl- --> NaCl • It takes one atom of sodium (Na) to combine with one atom of chlorine (Cl) to make the salt. • With stoichiometry, you can determine amounts of substances needed to fulfill the requirements of the reaction. • Stoichiometry will tell you that if you have ten million atoms of sodium (Na) and only one atom of chlorine (Cl) you can only make one molecule of Sodium chloride (NaCl). 10,000,000 Na+ + 1 Cl- --> NaCl + 9,999,999 Na+ • Nothing you can do will change that.

  25. Organic Chemistry • The chemistry of the compounds of carbon • “Organic” is a misleading name • Today most carbon compounds are synthesized • Usually from other organic compounds • Petroleum • Coal

  26. Carbon Compounds • Why so special? • Very, very many compounds • Molecules can be large and complex • Can attach themselves to one another to an extent not possible for atoms of any other element • Each different arrangement of atoms corresponds to a different compound • Each compound has its own set of chemical and physical properties.

  27. “The Age of Carbon” • Organic Chemistry is immensely important to technology • It is the chemistry of : • Dyes and drugs • Paper and ink • Paints and plastics! • Gasoline and rubber tires • Food and clothing • Biology and medicine

  28. Plastics are polymers • The most simple definition of a polymer is something made of many units. • "MER" is Greek for "part." • "POLY" is Greek for "many", • The long chain of "mers" forms a "POLYMER."

  29. Think of a polymer as a chain. • Each link of the chain is a monomer • Usually carbon, hydrogen, oxygen, and/or silicon. • To make the chain, many monomers are hooked or polymerized together.

  30. The Structure of Polymers • Many common classes of polymers are composed of hydrocarbons. • Carbon makes up the backbone • Hydrogen atoms are bonded along the backbone.

  31. The Structure of Polymers • There are polymers that contain only carbon and hydrogen. • Polypropylene, polybutylene, polystyrene, & polymethylpentene

  32. The Structure of Polymers • Other elements can also be involved • Polyvinyl chloride (PVC) contains chlorine • Nylon contains nitrogen. • Teflon contains fluorine • Polyester and polycarbonates contain oxygen.

  33. Characteristics of Polymers • 1) Polymers can be very resistant to chemicals. • 2) Polymers can be both thermal and electrical insulators. • 3) Generally, polymers are very light in weight with varying degrees of strength. • 4) Polymers can be processed in various ways to produce thin fibers or very intricate parts.

  34. Isomers • There are compounds with the same number of atoms but different shapes called ISOMERS.

  35. Carbon Compounds

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