1. 1) What is a chemical property?
Silently Begin. Do Now
1) What is a chemical property?
2) Water freezes at 0⁰C, is this a physical property
or a chemical property of water?
3) T/F Checking your weight on a bathroom scale is a
qualitative observation. (If false, fix the statement).
A characteristic of a pure substance that describes its ability to change into different substances.
quantitative

2. Announcements Due: Pages 16-21, Lab Reports Homework: Concept Map
USA TestPrep due Monday

3. Atoms, Elements, and Compounds
L.O. SWBAT describe how atoms, elements, and compounds are related.

4. Review
State of Matter can be used to describe physical properties. For example, water can be a solid (ice) or a liquid (liquid water), or a gas (evaporation).

5. Review
A chemical property of iron is that it will slowly combine with oxygen in the air to form a different substance, rust.

6. Elements What is an Element?
An element is a pure substance that cannot be broken down into any other substances by chemical or physical means.
Elements are the simplest substances.

8. Atoms
What is an Atom?
An atom is the basic particle from which all elements are made.
Atoms have a positive center (nucleus) surrounded by a negatively charged cloud.

9. When Atoms Combine
Atoms combine to form larger particles called molecules - groups of two or more atoms held together by chemical bonds.
A Chemical bond is a force of attraction between two atoms.
Atoms of most elements have the ability to combine with other atoms.

10. Molecule Example
For example think of the atoms hydrogen (H) and oxygen (O).
Alone, the are colorless, odorless, gasses.
When combined, they form a water molecule. O H
A molecule may be represented by a chemical formula, which shows the elements in the compound and the ratio of atoms.
For example: H2O The ratio of hydrogen atoms to oxygen atoms is 2 to 1. H O
H₂O

11. Compounds
A compound is a pure substance made of two or more different elements chemically combined in a set ratio.
represented by a chemical formula
For example: NaCl
Most elements in nature are found combined to other elements.
A compound may be represented by a chemical formula, which shows the elements in the compound and the ratio of atoms.
For example: NaCl The ratio of sodium atoms to chlorine atoms is 1 to 1.

12. Compounds
When elements are chemically combined, they form compounds having properties that are different from those of the uncombined elements.
For example:
Calcium (solid) + Carbon (solid) + Oxygen (gas)
= Calcium Carbonate

13. What is the difference between a molecule and a compound?
Think about it…
What is the difference between a molecule and a compound?
Molecules – 2 or more atoms combine
Compound – 2 or more DIFFERENT atoms combine

14. Concept Maps + Element Molecule Oxygen Oxygen O O₂ Element Oxygen O
Atom
Negative
electron cloud
Positive Nucleus
Atom
Negative
electron cloud
Positive Nucleus

15. Concept Maps + Element Oxygen O Compound Water H2O Element Hydrogen H
Atom
Element
Hydrogen H
Negative
electron cloud
Positive Nucleus
Atom
Atom
Negative
electron cloud
Negative
electron cloud
Positive Nucleus
Positive Nucleus

16. Remember properties of Matter… Did Mr. Edmond mention density?

17. Calculating Density

18. Mass (m) Amount of matter an object has.
SI Units: (International System of Units)
grams (g)
kilograms (kg)
Balance used for measurement
Lever balance
Triple-beam balance
Pan balance
Electronic balance

19. Weight (W) Force on the object due to gravity. SI Units: newton (N)
Balance used for measurement
Spring Balance
In science and engineering, the weight of an object is usually taken to be the force on the object due to gravity.[1][2] Its magnitude (a scalar quantity), often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g;[3] thus: W = mg. The unit of measurement for weight is that of force, which in the International System of Units (SI) is the newton.

20. Weight vs Mass
Triple beam balance vs a spring scale

21. Balance Used for Measurement
COMPARISON CHART
A. Triple-beam balance.
A. Quantity of matter in object regardless of volume or acting forces.
B. Measurement of the gravitational force acting on object.
B. Always constant at any place & any time.
A. Depends on the gravity at that Place.
A. Newton (N)
B. grams (g)
B. Spring Balance
DETAILS
MASS
WEIGHT
Definition
Effect of Gravity
Measurement
Balance Used for Measurement
Where does it fit?

22. Volume (V) How much space an object takes up. Regular Solid: Units:
base × width × height
Units:
cm3 m3 mL L

23. Volume of Liquids Irregular solids Measure displacement of water
1 mL = 1 cm3

24. Meniscus
curve of the liquid

25. Density (D) An objects mass divided by its volume. Density = Mass
Units:
g/cm3
kg/m3
g/mL
kg/L
Mass
Volume

26. Predicting Density

27. Review SI Units for . . . Mass Volume Density 5g , 80kg 10mL , 40L
.5 g/mL , 2 kg/L

28. Practice: Mass, Volume, or Density
40 kg
265 g/mL
0.67 g
42 cm3
71 g/cm3
Mass
Density
Possible White Board Questions.
Mass
Volume
Density

29. Calculating Density Write down the given information. D = V = m =
2. Plug information into formula.
3. Solve m V
D =

30. Summary (5 minutes silent writing)
Today I learned about…
Helper Questions
What is the difference between a molecules and a compound?
Define matter, mass, and volume.
How do you solve for density?

31. Homework Concept Map Choose a simple molecule or compound
On a separate sheet of paper make a concept map that relates atoms, elements, and the (molecule or compound).
Include the definitions for elements, atoms, and (molecules or compound).
Add color and designs, maybe a picture of your molecule or compound.

32. Homework + Definitions A molecule is… An element is… An atom is…
What does this look like?
Element
Oxygen O
Molecule
Oxygen O₂ +
Element
Oxygen O
Definitions
A molecule is…
An element is…
An atom is…
Atom
Negative
electron cloud
Positive Nucleus
Atom
Negative
electron cloud
Positive Nucleus