1. Quick Review A compound is made up of several ________. A column on the periodic table shows the_______. A row on the periodic table shows the_______. The atomic number represents the number of protons/electrons/neutrons in an atom. The atomic mass tells us the number of ______ and ______ in an atom

2. AtomProtonsElectronsNeutrons Helium Boron Group _______ & _______ contain the most reactive elements

3. Models of Matter Bohr Model (planetary model) –Electrons move around the nucleus in a circular orbits. –The farther away the electron the greater its energy. –Electrons cannot exist between these orbits, but can move from one orbit to another. –The order of filling of electrons in the first three orbits is 2, 8, and 8.

4. Model of The Atom Single particle of an element Cannot be broken down any further Contains nucleus (protons/neutrons) and shells (electrons)

5. Sample Bohr Models H Nucleus not showing protons or neutrons electron P

6. Phosphorous atom Bohr- Rutherford Diagrams 15p 16n We can combine Rutherford’s nuclear model with Bohr’s planetary model in diagrams that summarize the numbers and positions of all three subatomic particles in an atom.

7. 3. Draw the second orbit with the remaining electrons, 5. Nitrogen atom 2. Draw the first orbit with the maximum electrons allowed, 2. Sample Bohr- Rutherford Diagrams Create a diagram for Nitrogen. 1.Determine the number of electrons, 7 (same as atomic number). 7p 7n 4. Draw the nucleus with the protons and neutrons.

8. 4.Draw the third orbit with the remaining electrons, 2. 3. Draw the second orbit with the maximum electrons, 8. Magnesium atom 2. Draw the first orbit with the maximum electrons allowed, 2. Sample Bohr- Rutherford Diagrams Create a diagram for Magnesium. 1.Determine the number of electrons, 12. 12p 12n 5. Draw the nucleus with the protons and neutrons.

9. 3. Draw the second orbit with the maximum electrons, 8. Neon atom 2. Draw the first orbit with the maximum electrons allowed, 2. Sample Bohr- Rutherford Diagrams Create a diagram for Neon. 1.Determine the number of electrons, 10. 10p 10n 4. Draw the nucleus with the protons and neutrons.

10. Inside the Atom We have spent a great deal of time discussing atoms but what do they look like? Atoms are “particles” that are comprised of smaller particles called “subatomic particles”. –Electrons, protons, and neutrons are subatomic particles.

11. Inside the Atom - Protons Positively charge Mass of 1 atomic mass unit (amu). In the nucleus of the atom. The number of protons in an atom determines what an atom is. –For example, any atom with one proton is an hydrogen atom. The atomic number of an element indicates the number of protons in one atom of that element.

12. Inside the Atom- Electrons Negatively charge. Mass of 1/2000 of a proton. –And therefore don’t really contribute to the mass of an atom. Travel around the nucleus of the atom (orbit or energy level).

13. Inside the Atom- Neutrons Neutral particles. –neither positively nor negatively charged. Mass of 1. Found in the nucleus of the atom. The number of neutrons for a particular atom can vary  isotopes