1. Bell Ringer
We mentioned the Periodic Table of __________ yesterday.
A(an) _______ is the smallest part of an element.
An atom has four parts: the nucleus, ________, electrons, and neutrons.
Tell me what kind of charge each part has:
Proton ________
Electron _________
Neutron _________

2. Review of the Periodic Table of Elements
Goals for Today…
Review of the Atom
Review of the Periodic Table of Elements

3. Periodic Table of Elements

4. Dynamic Periodic Table

5. Draw the Element Square List….
Atomic Number _______
# of Protons _______
# of Electrons ________
Symbol _______
Name ________
Atomic Mass _________
Mass Number (Atomic Mass rounded) ________
# of Neutrons (Mass # - Atomic #)________
Create the atom

6. Chapter 4 Section 1 ( Part 2) Atomic Models

7. The first people to contribute to the development of atoms were Democritus and Dalton.

8. Democritus
430 B.C.- He used the word “atomos” (uncuttable) to describe the smallest possible piece of matter.
All matter was made up of small particles called atoms.

9. Points of Dalton's Theory:
The Dalton Model:
1803- John Dalton - English chemist that proposed first atomic theory
Points of Dalton's Theory:
All elements are composed of indivisible particles.
Atoms of the same element are exactly alike.
Atoms of different elements are different.
Compounds are formed by joining atoms of two or more elements.

10. Thomson and Rutherford Discovery
1897- J.J. Thomson discovered that atoms have negatively charged particles. (Electrons)
1911-Rutherford discovered that
atoms have a positive charge
and that the positive charge is
located in the center of the
atom called the nucleus.

11. 1913- Niels Bohr- showed that electrons could only have specific amounts of energy, causing them to move in certain orbits.
1920s- Scientists determined that electrons do not move in orbits but are moving in a cloud-like region known as the electron cloud

12. 1932- James Chadwick discovered that there was another particle in the nucleus with the same mass as a proton but neutral in charge

13. Atomic Model Video