1. Atoms
Smallest building block of matter

2. Atomic Structure
Nucleus is on the inside Electron Cloud is on the outside

3. Atomic nucleus
Center of the atom
Mass of the atom=protons + neutrons
Dense and tightly packed

4. Protons
Positive Charge
1 atomic mass unit

5. Neutrons
Neutral charge
1 atomic mass unit

6. Electrons Negative charge
Same number as protons so that atom is neutral.
Mass is so small, it is not counted.
Carbon has 6 protons, how many electrons?
Neon has 10 protons, how many electrons?
Argon has 18 protons, how many electrons?

7. Energy levels, shells Outside of the nucleus
Electrons move around very quickly in certain shells or energy levels.
Mostly empty space
because electrons are
so small.
Electrons in energy levels that
are farther away from
the nucleus have more energy.

8. Energy Levels hold electrons
The energy levels have numbers 1,2,3,4..
The first level holds two electrons the second 8, the next 18 and then all energy levels after that hold a maximum of 32.
The last energy level will never have more than 8 electrons.

9. Electron models
There are different models that represent how electrons move around the nucleus.

10. Opposites attract, likes repel
- protons_and_electrons
This holds the atom together

11. Atomic Number The number of protons in an atom.
Each kind of atom has a different atomic number.

12. Atomic Mass Protons + Neutrons There are different
atoms with different
atomic masses and numbers
of neutrons. These are
Isotopes.
The atomic mass is an
average of all the isotopes of a certain element.

13. Calculating neutrons Atomic mass-atomic number= number of neutrons
Atomic mass-number of protons =
Number of neutrons

14. What are the number of protons, electrons and neutrons for…

15. What is the atomic mass and atomic number for….
Strontium? It has 38 protons and 50 neutrons.

16. What is the atomic number and mass for Neon?

17. Review so far:
Name each part of the atom, its charge, location and mass.
What does the atomic number tell you?
What does the atomic mass tell you?
How do you figure out the number of neutrons?

18. What are the number of protons, electrons and neutrons for:
Argon, atomic # 18, mass;
Bromine; atomic #35, mass:
Germanium: atomic #32; mass: 72.61

19. Elements Elements are made of one kind of atom (H, O, S)
Their symbol is a capital letter (C for Carbon) or a capital and lower case (Fe for Iron)
How many elements are in:
FeS
COH Mg
Which of these are compounds?

20. Compounds They are made of more than one element, chemically bonded.
Bonds occur when electrons are shared or donated between two atoms.
Their formulas are the symbols for the elements with a subscript. H2O CO2
The smallest part of a compound is a molecule

21. How many atoms of each element are in:
C6H12O6
CH4
Fe2O3

22. Make a concept map of the words: Element Compound Molecule Atom

23. Models
Scientists developed theories for the structure of an atom, before they could see it.
They developed models. Which model do tyou think was developed first?

24. You can make a model! Move around the black disc.
Draw a picture of what you think the shape is.

25. History of ideas about the atom
Ancient Greeks believed the first elements were Fire, water, earth and air.
Dalton theorized that atoms were solid spheres.
The electron was discovered.
The proton was discovered.
Electrons were scattered about the atoms.
Rutherford discovered the nucleus was on the inside and electrons were on the outside.

26. http://reich-chemistry. wikispaces

27. Pictures of atoms
This is an image of two gold atoms. This picture was taken with an electron microscope

28. This is a topographic map of a silicon atom
Pictures of atoms
This is a topographic map of a silicon atom

29. Pictures of atoms
Silicon atoms on a surface. This picture was taken with a tunneling microscope.

30. How does this relate to something fun?
NBC learns : a microscope’s image of a molecule