ATOMS

1. ATOMS • It’s what makes us up!

2. ATOMS • The smallest particle which an element can be divided and still be the same substance.

3. Atom Size • 1 Penny= 2 x 10^22 Cu and Zn ATOMS • That’s (20,000,000,000,000,000,000,000) • Thickness of aluminum foil is about 50,000 aluminum atoms stacked up!

4. Parts of the ATOM • Protons (+) • Neutrons (0) • Electrons (-) NUCLEUS

5. Nucleus • ALL Protons (+) are identical. • Mass= 1 amu (atomic mass unit) • ALL Neutrons (0) are identical. • Mass= 1 amu

6. NUCLEUS • Most of the mass of an atom is found in the nucleus. • 1 amu= 1.7 x 10^ -24 g

7. PROTONS • Found in the nucleus • Positive charge • Mass= 1 amu • AMU= atomic mass unit- SI unit for measuring mass of atomic particles)

8. Atomic Number • Atomic Number= # of protons in an atom • ALL atoms of an element have the same number of protons!

9. Neutrons • Found in the nucleus • Neutral= no charge • Mass= 1 amu (atomic mass unit)

10. MASS NUMBER • Mass Number= protons + neutrons

11. ELECTRONS (-) • Found in Electrons Cloud Outside the nucleus. • In an atom: • # of protons = # of electrons • The atom has no charge! • Mass of an electron= almost 0 (We will call it zero)

12. ELECTRONS (-) • Comparing the masses • 1,800 electrons = 1 proton

13. Model of Atom

14. IONS • Charge particles • Positive ion • Protons (+) > Electrons (-) • Negative ions • Electrons(-) > Protons (+)

15. ISOTOPES • Atoms that have a different # of neutrons than protons. • The number of protons do not change!

16. ISOTOPES

17. Name that Isotope! • Write the name of the element! • Follow that with a hyphen. • And the mass of the isotope!