1. Properties of Matter
7th Grade Science

2. Partner Up! Find a partner
On the note card provided write down three characteristics you notice about your person that someone could use to distinguish them (these have to be things you can look at them to see)
Put YOUR initials on the back of the card
Turn this card in to Mrs. Weaver

3. Using only the characteristics on your card, try to figure out who your person is. When you think you know, raise your hand

4. What is a property?
A property is basically a characteristic of matter that helps you to distinguish what it is

5. Types of properties Extensive properties depend on the amount
Examples: mass or volume
Intensive properties do not depend on the amount
Examples: density and color

6. Physical properties can be measured without changing a substance’s identity. These include
Color
Density
Volume
Mass
Boiling point
Melting point
Why are boiling point and melting point not considered chemical properties?

7. Chemical properties are properties that become evident during or after a chemical reaction (so the substance would be changed to figure these out). Examples include:
Toxicity
Oxidation
Flammability
Heat of combustion
Enthalpy of formation
Chemical stability
radioactivity

8. Examples of properties
Hydrogen gas is very flammable
Sodium is highly reactive
Mercury is nonreactive
Fluorine reacts violently with water
Radium, plutonium and uranium are radioactive

9. The smallest form of an element is an atom
Draw an atom
Identify proton, neutron, electron
What is the nucleus? What makes up the nucleus?
The smallest form of an element is an atom
Pure elements are made up of the same type of atom

10. Atomic number
metals
Element symbol
nonmetals
Element name
metalloids
Atomic mass

11. Atomic number = the number of protons in the nucleus of an atom
Atomic mass = the total number or protons and neutrons it contains; the amount of stuff in the nucleus
You can figure out the number of neutrons by subtracting the atomic number from the mass number

12. Elements are grouped together on the periodic table by properties
Elements are grouped together on the periodic table by properties. Some are more reactive than others. What makes them reactive are the electrons. These electrons also give elements different chemical properties like conductivity, crystals, and oxidation

13. The most reactive elements are alkali metals, alkali earth metals and halogens
The least reactive elements are the noble gases

14. Atoms come together to form molecules
These molecules stick together in something called a bond. Some bonds are stronger than others depending on whether electrons are lost, gained, or shared
Water
Sodium Chloride
Xenon tetra-flouride