Do Now:
Define isotope
C-12   C-14    Na-23    H-3   U-236  U-235   H-2   C-13   Si-29   Na-22  K-40  Cl-35  K-39   Li-7  Fe-56

Write another symbol for each of these? How many neutrons in each of these.

Aim: To Explore the history of Atomic Structure

Materials needed:  Chalk/white board space, video, poster paper, models of s, p, and d orbitals (if models are not available bring in balloons or not.) Index cards with isotopes

Questions. What was the Plum pudding model( thomson’s model), Who was Dalton and what were his contributions? What did Rutherford’s experiment prove? What is the Bohr Model and draw an example using potassium. What is the quantum mechanical theory? What is the heisenberg uncertainty principle?

Notes: The modern model of the atom has evolved over a long period of time through the work of many scientists. Each atom has a nucleus, with an overall positive charge, surrounded by negatively charged electrons.
Subatomic particles contained in the nucleus include protons and neutrons.

The proton is positively charged, and the neutron has no charge.
The electron is negatively charged.
Protons and electrons have equal but opposite charges.
The number of protons is equal to the number of electrons in an atom. (Optional for review: Teacher will pass out handout for practice with protons, electrons and neutrons.)
The mass of each proton and each neutron is approximately equal to one atomic mass unit. An electron is much less massive than a proton or neutron.

In  the wave-mechanical model(electron cloud), the electrons are in orbitals, which are defined as regions of most probable electron location(ground state). Each electron in an atom has its own distinct amount of energy. When an electron in an atom gains a specific amount of energy, the electron is at a higher energy state (excited state.) When an electron returns from a higher energy state to a lower energy state, a specific amount of energy is emitted. The emitted energy can be used to identify an element.

Acitivity:

Students will break out into groups. Each will create a poster project and present to class. The topics: 1. rutherford experiment , 2. daltons atomic theory,  3. bohr model  4. electron cloud model (quantum theory)  5. Thomson model, plum pudding model p87-90

Each poster must include pictures, or drawings and pertinent notes about the topic.

Summary

history of atomic theory presentations

Homework

Read and study chapter 4

p113 #59-62
p112 #29-33