The document discusses the composition of atoms. It states that atoms are made up of three subatomic particles: protons, neutrons, and electrons. It provides details on the properties of each particle, including their charge (protons are positive, electrons are negative, neutrons have no charge) and mass (protons and neutrons have a mass of approximately 1 atomic mass unit, electrons have virtually no mass).

1. Launch Classify the following as either a ‘unit of measurement’, an ‘instrument’, or ‘neither’ L balance cm 3 mass kg mL volume g

2. What is the atom made of? Mr. Heffner Chemistry 9/1/09

3. What is matter made of? Matter = stuff All matter is made of atoms Atoms are really small!

4. What is the atom made of? The atom is the smallest unit , but still can be divided The 3 subatomic particles (sub = under, less than) Proton Neutron Electron

5. What is charge? Think about magnets… Two sides Red = positive (+) Grey = negative (-) Opposites attract ( Bill Nye Video ) Like charges repel

6. What is a proton? Proton Pro- = for Charge = +1 (positive) Mass = 1 amu Amu = atomic mass unit = 1.67 X 10 -24 g +

7. What is an electron? Electron Elect- = electricity Charge = –1 (negative) Mass = ~0 amu Actual mass = 9.109 X 10 -28 1,600 times smaller than a proton _

8. What is a neutron? Neutron Neu- = neutral Charge = 0 (no charge) Mass = 1 amu Same as a proton 0

9. Summary Atoms are made of 3 subatomic particles Proton – positive (+1) and 1amu Electron – negative (-1) and ~0amu Neutron – no charge (0) and 1amu

10. 8-way Foldable On the top of the flaps write the following: Atom Subatomic Particle Charge amu Proton Neutron Electron Matter Underneath each, write the definition Quiz yourself!

11. Practice Questions What are the 3 subatomic particles? True or False (and if false, re-write the statement so that it is true). “Like charges attract.” What is the charge on an electron? Which has more mass, a neutron or an electron? Fill in the following table: Subatomic Particle Charge Mass

12. Exit Slip Which of the following correctly lists the 3 subatomic particles? atom, ion, matter proton, isotope, electron krypton, proton, electron neutron, electron, proton A proton has a 1- charge 1+ charge 2+ charge no charge

13. Exit Slip Which of the following are true for neutrons? They have a mass of 1amu They are negatively charged They are neutral I only II & III I & III III only Protons have _______________ mass than neutrons. more less the same none of the above

14. Exit Slip True or False (and if false, re-write the statement so that it is true). “Electrons have virtually no mass and are negatively charged.”

15. Homework Vote for your question. The top two questions by majority vote will be reviewed.

16. Homework Finish the Practice Questions