What Are We Made Of?

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What Are We Made Of?
What are little boys made of? What are little
boys made of? Frogs and snails and puppy-dogs'
tails, That's what little boys are made of.
What are little girls made of? What are little
girls made of? Sugar and spice and all that's
nice, That's what little girls are made of.
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Objectives

• To learn about the composition of matter
• To learn the difference between elements and
  compounds
• To define the three states of matter

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The Composition of Matter

• Empedocles, 492-432 B.C. a Greek philosopher
  thought that matter was made up of four elements

• Democritus, 460 370 B.C. viewed matter as
  being made of atomos but he had no way of testing
  his hypothesis. That had to wait for another 2000
  years.

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A. The Particulate Nature of Matter

• Matter has mass and occupies space.
• It is composed of tiny particles called atoms.

One atom of aluminum is about 0.000000000000000000
000003 cubic centimeters in volume
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B. Elements and Compounds

• Elements

• Elements contain only one type of atom
  elemental copper contains only copper atoms and
  elemental gold contains only gold atoms.

What other elements occur, as pure elements, in
nature?
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B. Elements and Compounds

• Compounds

• Compounds are substances that contain two or more
  different types of atoms in a specific ratio.

How does the ratio of C to O in different samples
of carbon monoxide differ?
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Atoms and Molecules

• An Atom is the smallest particle that an Element
  can be divided into without losing its identity
• A Molecule is the smallest particle that a
  Compound can be divided into without losing its
  identity

But you will also hear O2, H2, N2 etc. referred
to as molecules
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C. The States of Matter

• Matter exists in three states
• Solid a rigid substance with a definite shape
• Liquid has a definite volume but takes the shape
  of its container
• Gas takes the shape and volume of its container

How do the volumes of solid, liquid and gaseous
water compare? What is in between the molecules?
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1912 Titanic Sinks
Where else are transitions between states of
matter important?