1. + + + + + + + - - - - -- - - + Elements and Atoms

2. Matter Matter - anything that has mass and takes up space (volume) Examples: A brick has mass and takes up space A desk has mass and takes up space A pencil has mass and takes up space Air has mass and takes up space

3. Atoms All matter is made of atoms Atoms are the smallest unit of matter An atom has 3 parts: –Protons – positive charge –Neutrons – no charge –Electrons – negative charge + + + - - - - +

4. Protons (+) Positively charged particles Very large size Found in the nucleus of the atom Equal to the atomic number of the atom Equal to the number of electrons + + + + + + + + - - - - -- - - +

5. Neutrons Neutral particles - no electric charge Found in the nucleus of the atom Very large size + + + + + + + - - - - -- - - +

6. Electrons (-) Negatively charged particles Found outside the nucleus in the orbits/energy levels Very, very, very small Move rapidly around the nucleus and create an electron cloud Equal to the number of protons - + + + + + + + - - - - -- - - +

7. Electrons (-) Each orbit/energy level can only hold a certain number of electrons Nucleus 1 st energy level 2 nd energy level 3 rd energy level

8. Electrons (-) Electrons in the outer most energy level are called valence electrons - used for bonding

9. Atoms Atomic Number = # of Protons = # of Electrons Protons + Neutrons = Mass Number

10. What element does this atom belong to? + + - = 1 = 0 = 1 - Hydrogen - H

11. What element does this atom belong to? + - = 8 Oxygen - O + + + + + + + - - - - - - - - +

12. What element does this atom belong to? + - = 11 = 12 = 11 Sodium - Na + + + + + + + - - - - - - - - + - - -

13. The Atom’s Nucleus Protons and neutrons are grouped together to form the nucleus of the atom - + + + - -

14. What is the atomic number of this atom? + + + - - - 3

15. What atom is this? + + + - - - Lithium - Li

16. What is the mass number of this atom? + + + - - - 3 protons + 4 neutrons = 7

17. What is the charge of this atom? + + + - - - 0 - Neutral

18. What is the charge of this nucleus? + + + - - - 3 - Positive

19. Isotopes Atoms that have the same number of protons, but have different numbers of neutrons The average of the masses of all the isotopes of an element = Atomic Mass (NEVER a whole number) + - + - + - Hydrogen (Protium) Mass # = 1 Hydrogen (Deuterium) Mass # = 2 Hydrogen (Tritium) Mass # = 3

20. APE MAN Atomic Number equals the # of Protons and Electrons Mass Number -Atomic Number equals the # of Neutrons

21. PEN What are the three subatomic parts of an atom? Protons Electrons Neutrons

22. Building Atoms Use the information below to: 1.Determine the # of electrons 2.Determine mass numbers 3.Determine their atomic number AtomsProtonsNeutronsElectrons Mass Numbers Atomic Numbers Aluminum1314 Nitrogen77 Fluorine910 Argon1822 Sodium1112 13 7 9 18 11 27 14 19 40 23 13 7 9 18 11

23. Atomic Mass vs. Mass Number Video https://www.youtube.com/watch?v=m15DW kkGe_0