1. Daily Science
Fill in and label all appropriate information about Manganese using the periodic table.
What’s the proton #
What’s the electron #
What’s the neutron # Mn

2. Bohr Models
Biology 1

3. Electrons Electrons – negatively charged particles.
1/1840th the mass of a proton.
In constant motion outside the nucleus.
Due to their negative charge, they are attracted to the positively-charged nucleus but remain outside of the nucleus because of the energy of their motion.

4. Electrons
Electrons orbit the nucleus of an atom in a prescribed path called an “orbital” or a “shell.”
The number of orbitals an atom has depends on its number of electrons.
There are limits on how many electrons can be in each electron orbital/shell.
1st Orbital: 2 electrons
2nd + Orbital(s): 8 electrons
Orbital 1 fills up first, then orbital 2, then orbital 3, and so on.

5. Electrons Valence Shell – the outermost orbital of an atom.
Valence Shell Electrons – the electrons found in the outermost orbital of an atom.
These valence shell electrons determine the physical properties of an atom (i.e. how it bonds with other atoms).

6. Electrons Hydrogen How many electrons? 1 How many orbitals?
How many electrons in its first orbital?
How many valence shell electrons?

7. Electrons Lithium How many electrons? 3 How many orbitals? 2
How many electrons in its first orbital?
How many electrons in its second orbital? 1
How many valence shell electrons?

8. Electrons Sodium How many electrons? 11 How many orbitals? 3
How many electrons in its first orbital? 2
How many electrons in its second orbital? 8
How many electrons in its third orbital? 1
How many valence shell electrons?

9. Bohr Models
Bohr Models are used to visualize individual atoms of different elements.
These allow you to see the number of valence electrons an element has, which is important because valence electrons determine the reactivity of an atom and thus its chemical properties.

10. Bohr Models Steps to a Bohr Model:
Determine the number of protons (p+), neutrons (n0), and electrons (e-).
Place protons and neutrons in the center.
Draw orbitals around the nucleus and label with the appropriate number of electrons.
Example: Hydrogen
1 p+, 0 n0, and 1 e-
1 e-
1p+
0n0

11. Bohr Models Example: Boron Example: Phosphorus 5 p+, 6 n0, and 5 e-

12. Free Late Pass Question!
Examine the structure of the periodic table very closely. What does it tell you about making a Bohr Model?