1. Nature of Matter
Chapter 2.1

2. Particles of an Atom
• Protons
– Positive charge
– Located in the nucleus
• Neutrons
– No charge (neutral)
– Located in the nucleus
• Electrons
– Negative charge
– Move around the nucleus

3. Atoms
• Basic unit of matter
• Extremely small
• Center region is called the
nucleus
• Made of protons, neutrons, and
electrons

4. Element
• Pure substance made of only one type of
atom
• Each is represented by a one or two-letter
symbol
• Examples
– Carbon, letter C
– Sodium, letter Na

5. Chemical Compounds
• Substance formed by combination of two
or more elements
• Example – Hydrogen and Oxygen
combine to form H2O (water)

6. Other Vocabulary Terms
• Macromolecule – made from hundreds or
thousands of smaller molecules
• Monomer – smaller unit of a larger
molecule
• Polymer – groups of monomers joined
together

7. Chemical Bonds
• Ionic Bond
– One or more electrons are moved or
transferred
– Example – NaCl (salt)
• Covalent Bond
– Electrons are shared by atoms
– Example – H20 (water)

8. Isotopes
• Atoms of the same element that have
different numbers of neutrons
• Example
– All atoms of carbon have 6 protons
– However, they may have 6, 7, or 8 neutrons

9. Carbon
• Carbon has four electrons for bonding
– Allows carbon to form four bonds
• Carbon compounds can also bond
with each other to form long chains
• Carbon is used to form many of the
molecules of living things

10. Carbon
• Carbon has four electrons for bonding
– Allows carbon to form four bonds
• Carbon compounds can also bond
with each other to form long chains
• Carbon is used to form many of the
molecules of living things