1. Chapter 4: Elements of Life
Reminder: Vocabulary Quiz Tomorrow!

2. What did you discover about surface tension from the lab on Friday?
What type of water had the highest surface tension? Lowest?
What errors/weaknesses did you see in the procedure?
What are your recommendations for future testing?

3. Periodic Table of Elements
What is this number?
Periodic Table of Elements

4. Atomic Number: Different for each element
Represents # of protons
Same # of electrons unless it is an ion (+/- charge)
Metals vs. Non-Metals
Metal: shiny, conductors of heat and electricity, high melting point, high density (heavy for their size), malleable (can be hammered), solid at room temperature, 1-3 electrons in the outer shell of each metal
Non-Metal: dull, poor conductors of heat and electricity, usually have 4-8 electrons in their outer shell

5. Review Element Trace Element Pure substance that can’t be broken down
Element that makes up less than .04% of your body mass

6. Ionic Bond Forms an Ion Attempt to create stable electrons
The goal is to have 8 electrons in the outer shell
When an element loses an electron it becomes + charged an when it gains an electron it becomes - charged

7. Creates a compound with 1 + and 1 - charged ion
Always between a metal and non-metal
Examples:

8. Baseball Game Example:
Each team is an atom, and the players are electrons. Team A is short one player and Team B has an extra player. Team A asks Team B to loan them a player. This exchange is similar to ionic bonding- the player (electron) is transferred from one team (atom) to another and the teams play (bonded).

9. Covalent Bond Formed by sharing one or more pairs of electrons
Two non-metals

10. If they are made from the same elements then the pull is equal
Create molecules
If they are made from the same elements then the pull is equal
With different elements one pull may be stronger, as seen in water
Hydrogen
Water

11. Baseball Game Example:
Suppose Team C has no pitcher and Team D has no catcher. Team D lets their catcher catch for both teams and Team C lets their pitcher pitch for both teams. The two teams (atoms), share two players (electrons), completing each team (atom).

12. Video Clips
Ionic and Covalent Bonding
Water Hydrogen Bonding

13. Metal and Non Metal = Ionic Bond
Two Non Metals = Covalent Bond

14. Chemical Reaction
Breaking of old bonds and formation of new bonds that create new substances
Give off or use up energy
Written form:
2K + Cl > 2KCl

15. Reactants
Products
Do not lose any elements, they are just rearranged

16. Assignment: Worksheet 4.1-4.4
Complete and turn in before the end of the period