BOHR Models and Valence Electrons Ms. Millimet August 19, 2013

Entrance procedure Enter the room silently Pick up papers you need for class Sit down at your table: Write down homework Get out homework from last night in first 2 minutes – Check with KEY Start DO First

Objectives Create a Bohr model for an atom that represents elements 1-18. Determine the number of valence electrons for any atom based on its a Bohr model of that atom.

Homework Review: Questions 5 and 6 What evidence do we have that supports our claim that these models represent Phosphorus and Neon? (Think: Atomic Number, Mass, Protons, etc.)

Bohr Model Practice Go over DO First Bohr Models Remember steps: Draw nucleus and write number of protons and neutrons Draw energy levels Draw electrons based on 2-8-8 rule 1st energy level – max 2 electrons 2nd energy level – max 8 electrons 3rd energy level – max 8 electrons

Valence Electrons Valence electrons are the electrons that are located in the outer-most energy level Valence electrons determine the physical and chemical characteristics of an element. Bohr models are extremely helpful in determining how many valence electrons an element’s atoms have.

Valence electrons These electrons Go back into Bohr models on Do First and circle the valence electrons!

Valence Electrons How many valence electrons does Magnesium have

Valence Electrons How many valence electrons does Neon have?

Practice APE MAN and draw a BOHR Model for the following elements. Label the number of valence electrons the atom has for: Chlorine Sodium Boron

BOHR Model UnFair Game! Create a Bohr model for an atom that represents elements 1-18. Determine the number of valence electrons for any atom based on its location on the Periodic Table or a Bohr model of that atom. Review: atomic structure, APE MAN

Unfair Game Only playing for 15 minutes  Prizes: 5 MERITS HOMEWORK PASS RESTROOM PASS Popsicles sticks will be pulled Write down answers in empty space under vocabulary box.

Question 1 How many protons are in a hydrogen atom? 1 proton

Question 2 How many neutrons are in a fluorine atom?

Question 3 How many protons, electrons, and neutrons are in one atom of argon?

Question 4 What element’s atom is represented below? Sodium

Question 5 How many valence electrons does this element have? 1

Question 6 A student creates a model of a helium atom. Which subatomic particles – and how many of each - would be found in the nucleus?

Question 7 Which element’s atom is pictured here? carbon

Question 8 How many valence electrons does this atom have? 2

Question 9 How many valence electrons does one atom of Fluorine have?

Question 10 How many valence electrons does one atom of Magnesium have?

Question 11 electrons

Question 12 Which subatomic particle determines an atom’s identity as a certain element? electrons

Question 13 Which subatomic particles are used to calculate the atomic mass? electrons

Question 14 What is the atomic mass of this atom? electrons

Question 15 What is the atomic number of this atom? electrons

Question 16 Which element is identified by having 16 protons?

More Practice and Exit Ticket Complete the practice and HW worksheet silently and independently Finish for HW With 8 minutes left – Exit Ticket! Put notes in your study buddy binder Take out periodic table and red pen to trade and grade