1. DRAW A BOHR MODEL OF ELEMENTS H TO CA ON THE PERIODIC TABLE OF ELEMENTS ATOM ANATOMY TARGET 1.3

2. MODELS OF ATOMS There are many different models of atoms We’ll use only one (for now) The Bohr Model You have probably seen it already…

3. MODELS OF ATOMS The Bohr Model compares the parts of the atoms to planets in orbit around a sun ◦ The electrons are the planets ◦ The protons and neutrons are the sun

4. MODELS OF ATOMS The protons and neutrons are at the center of the atom ( called the nucleus ) The electrons orbit the nucleus Just like planets, they all orbit at a certain distance

5. MODELS OF ATOMS Let’s look at helium Helium has: 2 protons in its nucleus 2 neutrons in its nucleus 2 electrons orbiting the nucleus ++ - -

6. MODELS OF ATOMS Let’s look at lithium Lithium has: 3 protons in its nucleus 4 neutrons in its nucleus 3 electrons orbiting the nucleus ++ - - + -

7. MODELS OF ATOMS Let’s look at sodium Sodium has: 11 protons in its nucleus 12 neutrons in its nucleus 11 electrons orbiting the nucleus 12N 11P - - - - -- -- - - -

8. MODELS OF ATOMS Let’s look at lithium Did you notice that even though lithium has three electrons, we only put 2 in the first orbit? + + - - + -

9. MODELS OF ATOMS For sodium, did you notice that we only put 8 electrons is the 2 nd orbit? 12N 11P - - - - -- -- - - -

10. MODELS OF ATOMS That’s the pattern: Only two (2) electron can fit in the first orbit Only eight (8) electrons can fit in the 2 nd orbit And only eight (8) electrons can fit in the 3 rd orbit

11. MODELS OF ATOMS POM Target 1.3: Draw a Bohr Model of Atoms Do your notes help you to do that?