Class Starter

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Class Starter

Identify the picture Identify the following and
their charge Red circles Charge Blue
circles Charge White circles Charge
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• The Nature of Matter
• Chapter 2.1

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Biochemistry Basics

• What is biochemistry?
• ?The study of the chemical substances and vital
  processes occurring in living organisms

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Matter

• Matter
• ?anything that has mass and takes up space
• Atom the smallest unit of matter
• Atoms make up elements

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Atoms

• Overall charge of an atom is neutral
• Nucleus the center of an atom
• Composed of protons and neutrons
• Protons
• ?positively charged subatomic particle
• Neutrons
• ?neutral/charge-less subatomic particle

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Atoms

• Electron orbitals areas surrounding nucleus
  where the probability of finding an electron is
  greatest
• ? also called electron clouds, energy
• levels, and electron shells
• Electrons negatively charged subatomic particle

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Atom Anatomy

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Isotopes

• ?Atoms of the same element containing different
  numbers of neutrons in the nucleus
• Some give off radiation used to
• Trace atoms through a reaction or an organism
• Treat cancer
• Date very old, once living organisms

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Nonradioactive carbon-12
Nonradioactive carbon-13
Radioactive carbon-14
6 electrons 6 protons 6 neutrons
6 electrons 6 protons 7 neutrons
6 electrons 6 protons 8 neutrons
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Review

• How is matter and atoms related?
• What are the 3 subatomic particles?
• Where are they located?
• What are their charges?
• What is a benefit to an isotope?
• How many electrons go on each energy level?

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Periodic Table

• Organized table that shows all of the elements

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Atomic Number

• Atomic number number at top of each box
  ?represents the number of protons or electrons in
  the atom

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Atomic Mass

• Atomic Mass
• ?the average weight of all the isotopes of a
  specific element
• found at the bottom of the box

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Drawing An Atom

• Step 1 Look at the atomic number and figure out
  how many protons are in the nucleus and how many
  electrons are floating around

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Drawing An Atom

• Step 2 Find the atomic mass and subtract from
  it the atomic number ? this will give you the
  number of neutrons in the nucleus

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Drawing An Atom

• Step 3 Put the protons and neutrons in the
  nucleus
• Step 4 Put electrons in orbitals
• 2 electrons can fit in the first orbital
• 8 electrons can fit in the second and third
  orbital

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Drawing An Atom

• Step 4 (Contd) Always fill the electron
  orbitals from inside out until all of the
  electrons are used
• Hint As you are inserting your electrons, make
  pairs of electrons in the orbitals

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Molecules

• Occurs when atoms combine together by a covalent
  bond
• Covalent bond forms when electrons are shared
  between atoms
• Ex Water
• ? Bonds are where energy is stored
• Why do they combine?
• To make all outer energy levels full of electrons

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Compounds

• A substance composed of two or more atoms of
  different elements joined by a chemical bond in
  definite proportions

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Ionic Bond

• Bond that forms when atoms either take electrons
  from or give away their electrons to other atoms

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Ions

• Atoms that have lost or gained electrons
• ?cation positively charged ion lost electrons
• ?anion negatively charged ion gained
  electrons
• Weaker than covalent bonds
• Hold less energy in the bond

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Figure 2-3 Ionic Bonding
Section 2-1
Sodium atom (Na)
Chlorine atom (Cl)
Sodium ion (Na)
Chloride ion (Cl-)
Transfer of electron
Protons 11 Electrons -11 Charge 0
Protons 17 Electrons -17 Charge 0
Protons 11 Electrons -10 Charge 1
Protons 17 Electrons -18 Charge -1
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Figure 2-3 Ionic Bonding
Section 2-1
Sodium atom (Na)
Chlorine atom (Cl)
Sodium ion (Na)
Chloride ion (Cl-)
Transfer of electron
Protons 11 Electrons -11 Charge 0
Protons 17 Electrons -17 Charge 0
Protons 11 Electrons -10 Charge 1
Protons 17 Electrons -18 Charge -1
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Van der Waals forces

• Attraction between oppositely charged areas of
  adjacent molecules
• ?weaker than covalent bonds and ionic bonds
• Ex.- Geckos ability to cling to
• walls

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Chemical Symbol

• Universal system to denote elements in the
  periodic table
• Example Oxygens symbol is O

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Chemical Formula

• Chemical Formula a group of symbols which shows
  the number and kind of each atom in a compound
• The subscripts found within a formula tells you
  the number of atoms of each element in that
  compound
• ?if there is no subscript, the number of atoms is
  then assumed to be one
• A number in front of the compound tells you how
  many of that compound you have

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Examples

• H2O2
• 3HCN
• C6H6
• 2C2H6