1. 8.6AB Atoms

2. Atoms • Atom • An atom is the smallest unit of an element, basic building blocks of all matter • The physical and chemical properties of an atom are seen in elements Click to play video

3. All atoms have 2 common structures: nucleus energy level(s)

4. - + + - Each structure is made of subparticles. energy level protons nucleus electrons neutrons

5. Atoms • Subatomic Particles • Atoms are made up of subatomic particles called: • Protons • Neutron • Electrons

6. Atoms • Subatomic Particles • Protons • Location: in the nucleus • Charge: positive charge • Mass: 1 amu (atomic mass unit) Protons

7. Atoms • Subatomic Particles • Neutrons • Location: in the nucleus • Charge: neutral (no charge) • Mass: 1 amu (atomic mass unit) Neutrons

8. A little joke… • A neutron walked into a bar and asked how much for a drink.  • The bartender replied,  "for you, no charge."  -Jaime - Internet Chemistry Jokes

9. Atoms • Subatomic Particles • Electrons • Location: in the electron cloud outside (surrounding) the nucleus • Charge: negative charge • Mass: 0 amu (atomic mass unit) Electrons

10. Atoms • Neutral Atoms • Neutral atoms: When the atom has the same number of protons and electrons • All elements (made up of atoms) on the periodic table are neutral

11. Is this atom neutral???

12. Is this atom neutral??? YES! It has the same number of protons and electrons 3 electrons (negative) 3 protons (positive)

13. Is this atom neutral???

14. Is this atom neutral??? No! 3 electrons and 2 protons 3 electrons (negative) 2 protons (positive) What type of charge does it have?

15. Is this atom neutral??? No! 3 electrons and 2 protons 3 electrons (negative) 2 protons (positive) Negative! Because there are more electrons (negative charges)

16. Atoms • Atomic Number • The atomic number tells you what element that atom is on the Periodic Table • The Periodic table puts elements in order by atomic number

17. Atoms • Atomic Number • Atomic number = # of protons • For example: Nitrogen has 7 protons so its atomic number of 7!

18. What is the atomic number of this atom?

19. What is the atomic number of Oxygen?

20. What is the atomic number of Helium?

21. Atoms • Atomic Mass • Atomic Mass: the mass of the atom • measured in amu (atomic mass units) • Atomic mass = Protons + Neutrons What is the atomic mass of Helium?

22. What is the atomic mass of this atom?

23. What is the atomic mass of Oxygen?

24. If you had the atomic mass and atomic number could you find the number of protons and neutrons?

25. To find the number of neutrons in an atom, subtract the atomic number from the atomic mass. 16 Atomic mass (protons + neutrons) - 8 Atomic number (protons) ___ 8 Number of neutrons

26. Atoms • Periodic Table • On the periodic table, you can find an atoms (elements) atomic number and atomic mass Here is the Key for each box

27. Atoms • Periodic Table Add the following to your periodic table # of protons or # of electrons protons + neutrons

28. Lets Review

29. 8 Atomic Number = 8 Protons= 16 Atomic Mass = + + + + + + + + + 8 Neutrons = 2 Energy Levels = oxygen atom 8 Electrons =

30. If both protons and neutrons are found in the nucleus, why is it positive? • Neutrons have a positive charge • Both neutrons and protons have a positive charge • Protons have a positive charge and neutrons have no charge • Neutrons have a negative charge

31. Atomic Structure VideoDiscovery Education