1. ATOMS and Molecules

2. ESSENTIAL QUESTION
How do we distinguish between atoms and molecules?

3. Definition of ATOM
is the smallest particle into which an element can be divided and still be the same substance

4. What is an Element?
Definition of Element: A substance that cannot be broken down into other substances by chemical or physical means.

5. WHAT’S THE BIG IDEA??
Atoms are composed of small particles that determine the properties of the atom.
There are three types of subatomic particles:
Neutron – neutral charge; holds the protons in the center of the atom (nucleus); largest
Proton -- positively charged particles; determines the identity of the element;
Electron – negatively charged particles; smallest; rapidly move around the nucleus

6. WHAT IS AN ATOM MADE OF?

7. ATOMS
The atom is held together by nuclear forces -- the positive protons and the negative electron attract each other.

8. ATOMIC MODELS (Bohr Model)
1. Nucleus -- protons and neutrons are in the center of the atom called the nucleus;
2. Electron Shells -- electrons travel outside the nucleus in "special orbits"; each orbit can only hold a specific number of electrons.

9. ATOMIC MODELS (Bohr Model)
FOR EXAMPLE:
Orbit #1 (closest to the nucleus) can hold only two (2) electrons.
Orbit #2 can hold up to eight (8) electrons.
Orbit #3 can hold up to eight (8) electrons.

10. What’s missing? Draw an arrow to it and Label
Electrons
Electron
Shell +
Protons
Nucleus

11. ATOMIC MODELS (Modern Atomic Model)
1. Nucleus - protons and neutrons are in the center.
2. Electron Shells -- a region around the nucleus of an atom where electrons are likely to be found.

12. Molecules are very small objects that are made up of connected atoms
What are Molecules?
Molecules are very small objects that are made up of connected atoms

13. What Do Molecules Look Like?
Molecules can take on all kinds of different shapes and sizes
Let’s look at a few!

14. Water H H O
H2O

15. Air
Nitrogen N
Oxygen O

16. Sugar
C6H1206

17. Salt (Sodium Chloride)
NaCl

18. It depends on whether they are in a solid, liquid, or gas
Do Molecules Move?
Yes, they do!
How do they move?
It depends on whether they are in a solid, liquid, or gas

19. Molecule Activity

20. Molecule Activity
1. Water
2. Carbon Dioxide

21. Molecule Activity
3. Ammonia
4. Methane