Bellringer

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Bellringer November 12, 2014

• Look at the Periodic Table
• What does the Au stand for?
• What atomic number is aluminum and what is its
  symbol?
• What 6 elements are WE mostly made up of? Look at
  the periodic table and take a guess!

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Chemistry

• Introduction to Chemistry
• Honors Biology
• Ms. Kim

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Composition of Matter

• Matter - everything in universe is composed of
  matter (stuff)
• Matter is anything that occupies space or has
  mass
• Mass quantity of matter an object has
• Weight pull of gravity on an object

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Chemistry of Life

• All matter is composed of tiny particles called
  atoms.
• There are 109 types of atoms - a substance
  madeup of one kind of atom is called an element.
  
• An atom is the smallest part of an element that
  still has the properties of that element.

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Atomic Structure
Each atom is made up of smaller parts called
protons, electrons and neutrons. Protons and
neutrons are found in the central portion of the
atom called the nucleus. Protons () in
nucleus Neutrons (0) in nucleus Electrons (-) in
a cloud outside!
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There are SIX elements necessary for life C
Carbon H HydrogenN Nitrogen O OxygenP
Phosphorous S- Sulfur

• CHNOPS
• The most important element is CARBON!

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Elements

• Therefore.
• Protons Neutrons Mass
• Mass - Atomic Neutrons

• Elemental Symbol
• Unique one/two letter symbol
• Atomic of a neutral element
• Equals the of protons AND the of electrons
• Unique for each element
• Atomic Mass -
• Avg. mass of an atom of the element (AMU)
• Equals the SUM of protons and neutrons

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The Nucleus

• Middle of the atom (central core)
• Holds positive charged protons and neutral
  neutrons
• Positively charged
• Contains most of the mass of the atom

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The Protons

• All atoms of a given element have the same number
  of protons
• of protons the atomic number
• of protons (s) of electrons (-s) (in a
  neutral atom)

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The Neutrons

• The number varies slightly among atoms of the
  same element
• Different number of neutrons produces isotopes of
  the same element

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Isotopes \ Isomers

• Isotopes an element with the same protons,
  but different neutrons
• Ex C-12 vs. C-14
• Isomers compounds with the same molecular
  formula, but different structures

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Practice Problems!

• How many protons does a sodium (Na) atom have?
• How many neutrons does a fluorine (F) atom have?
• What is the atomic mass for oxygen (O)?
• What is the atomic number for phosphorus (P)?

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The Electrons

• Negatively charged high energy particles with
  little or no mass
• Travel at very high speeds in different energy
  levels
• Energy levels are different distances from the
  nucleus

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Electron Shell
Electron Shell

• Shells
• Inner most ? can hold at most 2 e-
• Outer most ? can hold at most 8 e-
• Third outer most ? can hold at most 8 e-
• Elements want to have full shells, because this
  makes them stable!
• The electrons on the most outer shell is called
  VALENCE electrons
• EXAMPLE Carbon (neutral)
• Atomic 6 ? 6 total electrons
• 2 electrons fill the inner most shell
• 4 will be in the outer most shell
• This means Carbon has 4 VALENCE electrons
• Can bond to 4 other atoms!

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Periodic Table

• Elements are arranged by their atomic number on
  the Periodic Table
• The horizontal rows are called Periods tell the
  number of energy levels
• Vertical groups are called Families tell the
  outermost number of electrons

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Molecules and Compounds

• Molecules 2 atoms bonded together O2 for
  Oxygen
• Compound 2 elements bonded together - CO2 for
  carbon dioxide and NaCl for sodium chloride

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Compounds

• Compounds Examples
• Have different properties than individual
  elements
• Ex NaCl 1 sodium 1 chloride ? table salt
• Ex H20 2 hydrogen 1 oxygen ? water
• Ex NaOH 1 sodium 1 oxygen 1 hydrogen
• Ex CO2 1 carbon 2 oxygen

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Compounds

• What happens when the ratio of atoms changes?
• H20 vs. H2O2
• When the ratio of elements in a compound changes,
  the physical and chemical properties change too

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Molecules

• Molecule is two or more atoms held together by
  covalent bonds. Almost all of the substances that
  make up organisms, from lipids to nucleic acids
  to water, are molecules held together by covalent
  bonds.
• A compound is a type of molecule. All compounds
  are molecules, but all molecules are NOT
  compounds.
• Molecule Examples H2O, O2, O3
• Compound Examples NaCl, H2O

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Bonds

• Molecular glue
• Holds atoms together to form compounds
• Valence electrons are involved in bonding
• Valence electrons electrons on outer most
  energy level.
• Atoms are most stable when their outer most
  energy level is filled

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Bonding

• What holds atoms together?
• Atoms are held together by chemical bonds
• Goal to fill outer electron shellso atoms BOND
  together (share or give away/take electrons) to
  get a full outer shell
• 3 main types
• Ionic bonds
• Covalent bonds
• Hydrogen bonds

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Covalent Bonding

• Formed when two atoms SHARE one or more pairs of
  electrons. (co means together)
• When two or more atoms are joined by covalent
  bonds, we call this a molecule
• Covalent bonds are Very strong

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• Because positive and negative electrical charges
  attract each other ionic bonds form

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Ionic Bonds

• Formed when one or more electrons are transferred
  from one atom to another
• Atoms lose or gain electrons
• If an atom loses electrons ? becomes positively
  charged ()
• If an atom gains electrons ? becomes negatively
  charged (-)
• Atoms that have gained or have lost electrons are
  ions
• Ex Salt (NaCl)

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Cations Anions

• Cation when an atom loses an electron, it
  becomes more positively charged
• Positive Ion Cation
• Remember Cats have PAWS and are POSITIVE
• Ex Removing an electron from a K (potassium)
  atom will.create a POSTITIVE ION CATION
• Anion When an atom gains an electron, it
  becomes more negatively charged
• Negative Ion Anion
• Ex If a Cl (chlorine) atom gains an
  electroncreates a NEGATIVE ION ANION

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States of Matter

• Atoms are in constant motion (called kinetic
  energy)
• The rate at which atoms or molecules in a
  substance move determines its state

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Level of Organization

• Subatomic particles (p, e-, n0)
• atom (O)
• Element (O)
• molecule (O2)
• macromolecules (lipid)
• Cell (blood cell) lt--life begins here
• Tissue (epithelia tissue)
• Organ (lung)
• Organ system (Respiratory System)
• Organism (Panthera leo (lion))