1. Interactions of Matter and Energy
Chapter 9: Properties and Changes of Matter

2. What is Density? What is Matter?
Matter—anything that has mass and volume
Mass—amount of matter a substance is made of
Volume—amount of space taken up by a substance
What is Density?
Density—amount of mass divided by volume

3. What Are Physical Properties?
Physical Properties: properties such as color, shape, texture, order
Physical Properties Include:
Density
Ability to conduct electricity
Magnetism
Substance’s state: solid, liquid, gas

4. What Is a Physical Change?
Heat or removal of heat causes a change in state
Liquid—Solid—Freeze
Solid—Liquid—Melt
Liquid—Gas—Evaporation
Gas—Liquid—Condensation
Solid—Gas—Evaporation
Gas—Solid—Deposition

6. What Is a Physical Change?
Solid—Particles Vibrate in place
Add Heat
Liquid—Particles Slide past each other
Gas—Particles move rapidly in all directions

8. Elements and Atoms What Are Elements and Atoms?
Elements: substances that cannot be broken down into simpler substances
Atoms: tiny particles that make up elements

9. What Are Electrons, Protons, and Neutrons?
Nucleus: center of the atom
Proton: positive particle in the nucleus
Neutron: neutral particles in the nucleus
Electrons: negative particle surrounding the nucleus

11. How Have Ideas About Atoms Changed?
Dalton—atoms solid structure
Thomson—plum pudding model
Rutherford—Electrons surround nucleus
Bohr—electrons in orbits
Current—Electrons surround nucleus in electrons clouds

12. Atomic Number—number of protons in an element
Periodic Table arranged by atomic number

13. What is the Periodic Table?
Mendeleyev—organized elements by atomic mass—he left spaces and predicted properties of undiscovered elements
Periodic table reorganized by atomic number
Periodic table can be divided into metals, nonmetals, and metalloids

15. What Are Metals, Nonmetals, and Metalloids?
Most abundant type of element
Conduct electricity
Left side of periodic table
Non-metals
Properties opposite of the metals
Poor conductors of electricity
At room temperature gasses or solids
Right side of periodic table
Metalloids
Elements along the “stairway”
Properties of metals and nonmetals

16. Chemical Change What is a Chemical Change?
Chemical change: substance formed with new or different properties
Compound: chemical combination of two or more substances

17. What are Chemical Bonds?
Chemical bond: atoms join together to for molecules or new substances
Chemical formula: way of using letter and numbers to represent atoms bonding together

18. How Do Covalent Bonds Form?
Covalent Bonds: Atoms share electrons when they bond
Covalent bonds usually formed by nonmetals

20. How Do Ionic Bonds Form?
Ionic bonds form when electrons are given or taken away
Charged particles attracted to each other and form a bond
Ion: charged particle
Give up an electron—become positive
Gain an electron—become negative

22. What Are Chemical Reactions?
Reactants—starting substances
Products—ending substances
3 Types of Chemical Reactions
Synthesis-
Replacement
Decomposition

23. Synthesis: two separate substances join together
Decomposition: substance breaks down into two simpler substances
Replacement: element replaces another or switch position

24. What Are Element’s Chemical Properties?
Chemical Property: How a substance responds or reacts with other substances
Location on the periodic table can be used to predict the chemical properties of an element
Last column of the periodic table (right)—noble gases