1. ATOMS, ELEMENTS COMPOUNDS AND MIXTURES 7-5.1 & 7-5.2

2. ATOMS
Matter is composed of extremely small particles, too small to be seen with a classroom microscope, called atoms.
Atoms: smallest part of an element that has the chemical properties of the element.
A single atom has mass and takes up space.

3. PARTS OF AN ATOM Electron: Proton: Neutron:
smallest part of an atom
Charge: negative
Orbits around the atom (like moon around planet)
Proton:
Postive charge
In the nucleus of the atom
# of protons defines the atom
Neutron:
No charge because they are neutral
Nucleus of atom: made of neutrons and protons

4. Electron Location Innermost ring holds 2 electrons
2nd ring can hold up to 8
3rd ring can hold up to 18
4th ring can hold up to 32
The more COMPLETE the outermost ring is, the more “stable” the atom will be.

5. MODEL OF ATOM
Watch Brain Pop

6. ELEMENTS
Elements: pure substances that cannot be changed into simpler substances.
Elements are composed of one kind of atom.
Ex: Gold, Oxygen, Silver, Helium, Hydrogen
All elements found on periodic table

7. COMPOUNDS
Pure substances that are composed of two or more types of elements that are chemically combined.
Compounds can only be changed into simpler substances called elements by chemical changes.
One way that two or more atoms can combine is to form a molecule.
Ex: H2O, CO2, C6H12O6

8. MIXTURES
Composed of two or more different substances that retain their own individual properties
Combined by physical means
Can be separated by physical means (filtration, sifting, or evaporation).
Mixture may be heterogeneous or homogeneous.

9. TYPES OF MIXTURES heterogeneous mixture Not uniform (same) throughout
Substances can be visibly distinguished
Ex: Salad, bag of sand and rocks
homogeneous mixture
Uniform throughout
Substances can not be visibly distinguished
Another name = solution
Ex: Salt water and kool aid
**Brain pop

10. MATTER