1. Atomic Structure Chapter 3.1

2. Subatomic Particles Proton +1 charge, found in the nucleus Neutron No charge, found in the nucleus Electron -1 charge, found outside of the nucleus Nucleus The area in the center of the atom

3. Net Atomic Charge There are equal numbers of ____ and _______. They have equal and opposite charges. This gives the atom an overall _______ charge.

4. Atomic Models Democritus John Dalton Niels Bohr Electron Cloud Model

5. p n Bohr Model - Hydrogen e Energy Levels (or Electron Shells) Level Capacity 1 st – 2 electrons 2 nd – 8 electrons 3 rd – 8 electrons 4 th – 16 electrons Nucleus

6. 8p 8n Bohr Model - Oxygen 2e Energy Levels (or Electron Shells) Nucleus 6e

7. Electron Cloud Model The electrons are in “ orbitals, ” not energy levels. Orbitals Location of high probability for finding an electron. This is where the “ cloud ” idea comes from.

8. Table Structure Chapter 3.2

9. Periodic Law Def. Properties of the elements change in a regular pattern on the Periodic Table Examples Metal / Nonmetal Reactive / Nonreactive Solid / Gas (at room temp.)

10. The Periodic Table Elements are numbered in order by the number of PROTONS in an element. The table is organized by the ELECTRONS in an element. Specifically, the VALENCE electrons

11. IONS Sometimes atoms lose or gain electrons. This effects their overall charge. They can become positive or negative. Def. an atom that has gained or lost an electron.

12. Why do the Electrons Change? Atoms have 2 requirements they want to fulfill. 1. They want to be neutrally charged. 2. They want a full outer shell of electrons. These two requirements are not always compatible together.

13. Types of Ions Cation Positively charged ions They ___ electrons. Examples Ca 2+ K + Anion Negatively charged ions They ___ electrons. Examples Cl - O 2-