4. nucleus of atom +

7. Protons OSITIVEOSITIVE + Neutral OCHARGEOCHARGE Electrons NGATIVENGATIVE - +

8. The Atom - Charge Charge can be Neutral, Positive or Negative

9. Charge is equal to 0

10. Charge is equal to +1

11. Charge is equal to -1

12. What do you notice about the periodic table?

13. The whole numbers (above the element symbol) increase across the rows. 3 4 5 6 78910

14. The whole numbers are the Atomic Numbers.

15. Carbon has an atomic number of 6. Carbon has 6 protons.

16. The atomic number (number of protons) determines the identity of the element. B 5 10.811 Boron C 6 12.011 Carbon N 7 14.007 Nitrogen So, if you change the number of protons, you change the element.

18. What else do you notice about the periodic table?

19. There are decimal numbers below the element symbol. 6.941 1.0002 10.811 12.01114.00715.99918.99820.180

20. The decimal numbers are the Atomic Masses.

23. 2.0164186 amu + 0 amu Mass of an atom with one Proton, one Neutron and one Electron. Mass of an atom with one Proton and one Neutron. 2.01587 amu

24. Electrons are too small to change the mass of the atom. Protons and Neutrons determine the Atomic Mass.

25. –Isotopes = atoms of the same element that have different numbers of neutrons Carbon-12 6 neutrons + + + + + + 7 neutrons Carbon-13 + + + + + +

26. 12 amu 13 amu Mass of Carbon-12 Isotope is 12 amu Mass of Carbon-13 Isotope is 13 amu

28. Carbon has an Atomic Mass of 12.011. 12.011 rounds to 12. So, the Mass Number of carbon is 12 amu. Since the mass of each proton and each neutron is 1 amu and the atomic mass of Carbon is 12 amu, there are 12 protons and neutrons in a Carbon atom.

29. Atomic Mass Atomic Number

30. Atomic Number For example: Carbon has 6 protons. For example: Carbon has 6 electrons.

31. Atomic Mass For example: Carbon has a Mass Number of 12 and an Atomic Number of 6. 12 – 6 = 6 So, Carbon has 6 neutrons.

32. Do you notice anything else about the periodic table?

33. There are roman numerals above each column. IA IIAIIIAIVAVAVIAVIIA VIIIA

34. The roman numerals are the Group Numbers.

35. Group IIA elements = 2 valence electrons