Objective: identify the three subatomic particles and compare their properties.

1. Objective: identify the three subatomic particles and compare their properties. DO NOW List all the information you know about the subatomic particles.

2. The Structure of an Atom • The beams seen in Thomson’s experiment are similar to the ones that are used to create color television. • There are 3 beams, one for each primary color and the beams are made from subatomic particles (red, green, and blue)- swinging ball demo)

3. Properties of Subatomic Particles • Protons • + charged • Found in the nucleus • half the atoms mass • Neutrons • No charge • Found in the nucleus • half the atoms mass • Electrons • - charged • outside the nucleus • Are so small their mass does not affect the mass of the atom

4. Comparing Subatomic Particles • Can be distinguished by charge, location, and mass in an atom • Protons and neutrons have almost identical masses, but takes about 2000 electrons to equal the mass of 1 proton or neutron • Protons and electrons have equal and opposite charges • Protons and neutrons are found in the nucleus • Electrons are found in the space outside the nucleus

5. Atomic Number and Mass Number • Each elements has a unique # of protons • Atomic Number • Protons and electrons • Mass Number • protons + neutrons If you know the atomic number and the mass number you can figure out the number of neutrons

6. Isotopes • Atoms of the same element that have different numbers of neutrons and different mass numbers • Every atom of Oxygen has 8 protons so the atomic number stays the same. Atoms of Oxygen can have 8, 9, or 10 neutrons. • These isotopes are identified by their mass number • Oxygen-16 • Oxygen-17 • Oxygen-18

7. Objective: identify the three subatomic particles and compare their properties • Homework: page 112 questions 1-9