1. Atomic Structure and Chemical Bonds
Chapter 6
Atomic Structure and Chemical Bonds

2. Foldable Hamburger fold Cut along the seam
Label top half “ Ionic Bonds”
Label the Bottom Half “Covalent Bonds”

3. Key Vocabulary Electron cloud Energy level Electron dot diagram
Chemical bond
Ion
Ionic Bond
Compound
Metallic Bond
Covalent Bond
Molecule
Polar Bond
Chemical Formula

4. Atomic Structure
Your desk appears to be solid, but it is mostly empty space…
Electron cloud- the area of open space around an atom’s nucleus that contains electrons
The path of an electron is not well mapped. It is actually kind of random

5. Electron cloud Very similar to the blades of a ceiling fan
It appears that there is a circle rotating when it is a few blades moving at such a fast rate that it creates that image

6. Electron arrangement
Although all the electrons are in the electron cloud, some electrons are closer to the nucleus than others
Energy Levels- different areas for an electron in an atom
Look at figure 3 on page 163

7. Number of Electrons
Each energy level can only hold a certain number of electrons
Energy Level One- can hold either 1 or 2 electrons
Energy Level Two- can hold up to 8 electrons
Energy Level Three- can hold up to 18 electrons
Energy Level Four- can hold up to 32 electrons

8. Quick Lab Get a magnet and 4 paper clips
Use the magnet to pick up one paper clip—record observations
Use the magnet to pick up the rest of the paper clips one at a time—record observations
One at a time remove the paper clips from the magnet—record observations
Which paper clip was the easiest to remove? Why?

9. Energy Levels
Electrons in energy level one have the least amount of energy and are less likely to leave the atom
Electrons in energy level 4 have the most energy and are more likely to leave the atom

10. Periodic Table and Energy Levels
The number of electrons increases by one as you go across a period
The number of energy levels increases by one as you go down a column
“Eight is Great”

11. The Noble Gases
All noble gases either have all of their energy levels filled to its maximum or it has eight electrons in its outermost energy level

12. Quick Check-up How many energy levels?
Calcium
Strontium
Boron
How many electrons in outermost level?
Antimony
Beryllium
Krypton

13. Periodic Families Group 18- Noble Gasses Group 17- Halogens
Do not combine with other elements
Some react slightly, but it is rare
Group 17- Halogens
Very reactive- only needs one electron to be stable
Flourine is the most active, outermost shell is closest to the nucleus
Group 1- Alkali Metals
Have one electron in outermost shell
Very reactive with halogens

14. In your Science Journal
Read and answer the questions in the “Applying Science” article on page 167

15. Electron Dot Diagrams Write Chemical Symbol
Place first dot on top of symbol and work right until all four sides have a dot or you are out of electrons
Only use electrons in the outermost energy level. Why?
Starting back at the top fill in the remaining spaces until you are out of electrons

16. Chemical Bond The force that hold atoms together
Atoms bond in manner which makes both atoms stable
i.e: both atoms outermost shells will be arranged like the noble gasses (8 Electrons)

17. Ionic Bonds
Ion- result of an atom loosing or gaining an electron and changing its overall charge
Ionic bond is an attraction which holds ions together
Compound- pure substance containing two or more elements that are chemically bonded

18. What happens…
If Magnesium (+2 charge) meets with chlorine (-1 charge) will they bond? If so, How?

19. Metallic bonding Form when metal atoms share their pooled electrons
Keeps metals from breaking and makes them malleable
The outermost electrons travel from one atom to another enabling a current

20. Covalent Bonding
The chemical bond that forms between non-metal atoms when they share electrons
Form a neutral particle
Molecule- neutral particle formed when electrons are shared

21. Diatomic Molecules Hydrogen Oxygen Nitrogen Fluorine Chlorine Bromine
Iodine
Astatine

22. Double and Triple Bonds
Sometimes an atom shares more than one electron with another atom
Look at figure 17 on page 174 for double bond
When two pairs of electrons make one covalent bond it is called a double bond

23. Double and Triple Bonds
Figure 17 also shows a triple bond between 2 Nitrogen atoms
This occurs when three pairs of electrons are shared covalently

24. Polar Molecules Ball Demo Polar Bond
2 different sizes, one is positive and one is negative
Polar Bond
When atoms of different sizes bond, they form polar molecules
These molecules do not share the electrons evenly
The larger atom keeps the electrons more than the smaller atom

25. Polar Molecules A good example of a polar molecule is water
Also, hydrochloric acid and sodium chloride
Draw these three molecules and determine the poles.

26. Chemical Symbols
You all have been asking how elements get their symbols
Most elements are symbolized by their first letter
Examples: Hydrogen (H) and Carbon (C)
Others are symbolized for their name in another language
Potassium (K) – Latin for Kalium
Iron (Fe) – Greek for Ferrous
Chemical symbols are understood worldwide

27. Chemical Symbol Rules If One Letter: If Two Letters: If Three Letters:
Must be capitalized
If Two Letters:
First letter is capital and the second is lowercase
If Three Letters:
First letter is capitalized and the remaining are lowercase

28. 2 H2
Superscript
Subscript
Chemical Symbol

29. Common Chemical Formulas
Hydrochloric Acid
Sodium Chloride
Sodium Hydroxide
Sulfuric Acid
Silver Nitrate
Iron Oxide
Water
Hydrogen Peroxide
Ammonia
Nitric Acid
Acetic Acid
Magnesium Chloride