1. General Science– Structure of Matter, Chapter 2
Properties
Molecules
Atoms
Elements
Periodic Table Symbols
Using the Periodic Table
Compounds

2. Lesson 1: Properties of Matter
Matter – is anything that contains mass and takes up (or occupies) space. A property is a characteristic of matter that helps identify it. TWO types of properties: Chemical: describe how kinds of matter react with other kinds of matter. (ie. reactivity, pH, electron structure, etc) Physical: all other properties (size, shape, color, texture, density) Some properties are used to identify matter (density, boiling and freezing point, etc).

3. Categories of Matter

4. Lesson 2: Molecules
All matter is made up of atoms – the basic unit of matter.
More than one atom bonded together makes a molecule.
If the atoms bonded are different, you have a compound; ie. H2O.
Many elements consist of molecules that only contain one atom; ie. N2, O2, I2. These are called diatomic.

5. Density and States of Matter
Density – an identifying property of matter
Gas – no definite shape or volume (fits a container)
Liquid – definite volume but no definite shape
Solid – definite shape and volume
Plasma – very high energy, ie. lightening. Charged particles
Density is how tightly material is packed into a given volume. Is calculated by dividing mass by volume: g/ml; g/cm3

6. Lesson 3: Atomic Structure
Many different models of the atom have been suggested over time. Models are used to help us imagine what atoms are like.

7. Over time, scientists have found that atoms are mostly empty space but consist of electrons, protons and neutrons.
Electrons zoom around the inner nucleus
Most of the atom’s mass is in the nucleus
Nuclei contain protons and neutrons that have 1000x more mass than electrons
Electrons have a negative charge, protons have a positive charge and neutrons have no charge
Good video on Rutherford’s discovery of the nucleus

8. Uncharged atoms always contain the same number of protons (+) and electrons (-)
Neutrons add mass but don’t change the element type

9. Lesson 4 & 5: Elements & Symbols
Atoms of one type make up an element. Which element depends upon the number of protons.
An element is a substance found in nature.
Natural elements are present in nature (vs. synthetic or laboratory elements)
Living things contain many elements but not all of them
All known elements are found in the periodic table.
Elements each have a symbol.
Periodic table is arranged by atomic number
The atomic number is the # of protons in each atom of one element.

10. Elements that make up organisms

11. Lesson 6: The Periodic Table
Info Element on The Table: # protons # electrons Mass # neutrons Ionic charge

12. How to find this info on the table.
The atomic number is the big number in each square.
Atomic number = # protons
# protons = # electrons
Mass - # protons = # neutrons
Practice

13. Isotopes
Isotopes: All atoms of one element have the same number of neutrons. However, they can have different neutron #’s = different masses.

14. Compounds Several atoms bonded together are molecules.
Molecules can be made of the same atoms (called diatomic elements)
Ie. oxygen, O2; fluorine, F2; nitrogen, N2; ozone, O3. OR
Molecules can be made of different atoms (called compounds)
Ie. water H20; carbon dioxide CO2; glucose C6H12O6
Mixtures: physically combined elements or compounds that can be separated. Compounds have different properties than their elements.