1. INTRO TO THE ATOM TIM WALSH MILFORD HIGH SCHOOL CONCEPTS OF CHEMISTRY 2015-2016

2. Atom The smallest unit of an element. All atoms of a single element are identical (nearly).

3. Element Krypton

4. Element Carbon

5. Element Mercury

6. Atom It is NOT the smallest particle

7. Electrons (-) Protons (+) Neutrons (0) Nucleus Atom

8. Subatomic Particles: Protons Positively Charged! Have mass! (1 amu) Part of the nucleus 3 amu due to protons!

9. Subatomic Particles: Protons The number of protons defines an element Carbon has 6 protons Iron has 26 protons Bromine has 35 protons Zinc has 30 protons

10. Subatomic Particles: Neutrons Neutral Charge! Have mass! (1 amu) Part of the nucleus 4 amu due to neutrons!

11. Subatomic Particles: Electrons Negatively Charged! No mass! Orbit the nucleus in 3D Space In an atom, the number of electrons is the SAME as the number of protons.

12. Atomic Number Number of protons in an atom of the element OR The number of electrons for the base element Periodic Table- Element Boxes + + + + + + - - - - - -

13. Elemental Symbol Abbreviation for an element (if two letters, the first is capital and the second is lowercase) Periodic Table- Element Boxes

14. Atomic Mass Average mass of an atom of the element (unit: amu or g/mol) OR Number of protons and neutrons Periodic Table- Element Boxes + + + + + + 0 0 0 0 0 0

15. Atomic Mass Atomic Number + + + + + + 0 0 0 0 0 0 Atomic Mass – Atomic Number = Number of Neutrons