The Chemistry of Life

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The Chemistry of Life
Chemistry The science of the composition,
structure, properties, and reactions of matter.
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Whats this matter?

• Matter anything that occupies space (has volume)
  and has mass
• In non-scientific terms STUFF like books,
  submarines, belly button lint
• Everything is matter (except memories etc)
• So if everything is matter, how do we divide
  matter up?

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Remember, the smallest division of an element
that retains the characteristics of the element
is

• An atom

• Elements are made of a single kind of atom and
  cannot be broken down by chemical means into
  simpler substances.
• Most common elements in living things C,H,O,N,S,P

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So EVERYTHING IS MATTER AND CONTAINS ATOMS, BUT
WHAT ARE ATOMS MADE OF???????

• Atoms are composed of protons, neutrons, and
  electrons.

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The Atom

• Protons and neutrons in the nucleus
• Electrons move about the nucleus in orbitals.
• Pe in neutral
• atom
• Subatomic particles
• Protons - positive charge
• Electrons - negative charge
• Neutrons - no charge

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Electrons

• Located outside of the nucleus
• Unless otherwise indicated the number of
  electrons (-) is the same as the number of
  protons () in a neutral atom (0).
• Electrons orbit the nucleus in levels.
• Only electrons in the outermost energy level are
  involved in chemical reactions

Remember Number of electrons number of
protons in neutral atom
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Outer Shell Electrons

• Atoms seek to have a full outer shell of
  electrons (8).
• So, if an atom has five, it will seek out a way
  to share or steal three electrons with other
  atom(s).
• Atoms with full shells are very stable
• Example Group 8ANoble Gas are unreactive

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Electrons are found on energy levels

• The first energy level is closest to the nucleus
  and fills with 2 electrons.
• The second energy level is a bit further from the
  nucleus and fills with 8 electrons
• The third energy level is even further away from
  the nucleus and fills with 8 electrons.

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Electron Arrangements
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Atomic Number

• The number of protons
• All atoms of same element have same atomic number
• Atomic number gives identity to element

Periodic table is arranged by order of atomic
number!
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• Isotopes
• Atoms of the same element that have a different
  number of neutrons are called isotopes.
• Isotopes are atoms of the same element (same
  protons) but different mass numbers

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Mass Number

• Mass number is the Number of protons Number of
  neutrons.
• It is not a whole number because it takes into
  account the relative amounts of isotopes.

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How many protons and electrons in each isotope?
Atomic ?
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How about neutrons and mass number?
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Elements are Organized in the Periodic Table

• Back cover of text
• Elements symbolized by 1, 2, or 3 letters
• What element is
• C -Cl
• O -F
• Shows
• Atomic Number
• Chemical Symbol
• Atomic Mass (Not whole-accounts for isotopes)
• Mass Number (whole number of protons plus
  neutrons)

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Lets Practice

• Element?
• Atomic Number?
• Atomic Mass?
• How many protons?
• How many neutrons?
• How many electrons in a neutral atom?

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Lets Practice

• Element?
• Atomic Number?
• Atomic Mass?
• How many protons?
• How many neutrons?
• How many electrons in a neutral atom?

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End of Notes
Hooray!!!!

• Homework
• Atomic Structure Worksheet
• Read pages 28-31
• Complete the vocab for section 2.1 and parts of
  2.2 (ask teacher)