1. The Amazing Atom

2. Atoms All matter is made of very tiny particles All matter is made of very tiny particles These atoms have the same properties as larger particles of These atoms have the same properties as larger particles of the matter have

3. Parts of the Atom Subatomic Particles – smaller than an atom (parts) Subatomic Particles – smaller than an atom (parts) Proton Proton Neutron Neutron Electron Electron

4. Subatomic Particles Protons (p + ) Protons (p + ) Positive charge Positive charge Each one has a charge of +1 Each one has a charge of +1 Located in the nucleus Located in the nucleus Each one has a mass of 1amu (atomic mass unit) Each one has a mass of 1amu (atomic mass unit)

5. Subatomic Particles Neutrons (n 0 ) Neutrons (n 0 ) No charge No charge Located in the nucleus Located in the nucleus Each one has a mass of 1amu (atomic mass unit) Each one has a mass of 1amu (atomic mass unit)

6. Subatomic Particles Electrons (e - ) Electrons (e - ) Negative charge Negative charge Each one has a charge of -1 Each one has a charge of -1 Located in the space (cloud) around the nucleus Located in the space (cloud) around the nucleus Each one has a mass of about 0.0006amu (atomic mass unit) Each one has a mass of about 0.0006amu (atomic mass unit)

8. The Atom The nucleus has p + and n 0 The nucleus has p + and n 0 Positively charged Positively charged The electron cloud has e - The electron cloud has e - Negatively charged Negatively charged The number of protons equals the number of electrons in a neutral atom The number of protons equals the number of electrons in a neutral atom

9. Periodic Table The periodic table gives us lots of information about the elements. The periodic table gives us lots of information about the elements. 1 H Hydrogen 1.008 Atomic Number Element Symbol Element Name Average Atomic Mass

10. Symbol Practice For the element name, give the symbol. HeliumCarbonSulfurOxygenMagnesium

11. Element Practice For the symbol, give the element name. LiNArAlNa

12. Atomic Number Atoms of different elements are different Atoms of different elements are different The number of protons in the nucleus is the atomic number of an element The number of protons in the nucleus is the atomic number of an element

13. Atomic Number The atomic number identifies the element The atomic number identifies the element Like DNA Like DNA for an element

14. Proton Practice Practice: How many protons are in each of the following elements? CarbonPotassiumNitrogenCalciumSilicon

15. Electrons Electrons give atoms their chemical properties Electrons give atoms their chemical properties In order for an atom to have a neutral charge, it must have the same number of electrons as it has protons. In order for an atom to have a neutral charge, it must have the same number of electrons as it has protons. Electrons = protons = atomic number Electrons = protons = atomic number

16. Electron Practice Practice: How many electrons are in each of the following elements? HeliumChlorineNitrogenAluminumBoron

17. Mass Number All atoms have a mass number All atoms have a mass number We can figure it out by rounding the Average Atomic Mass to the nearest whole number We can figure it out by rounding the Average Atomic Mass to the nearest whole number Mass number = protons + neutrons Mass number = protons + neutrons Neutrons = Mass number – protons Neutrons = Mass number – protons

18. Finding Neutrons Example: Carbon Example: Carbon Round the Average Atomic Mass to the nearest whole number: Round the Average Atomic Mass to the nearest whole number: 12.01 rounds to 12 How many protons in carbon? How many protons in carbon?6 Neutrons = Mass number – protons Neutrons = Mass number – protons Neutrons = 12 – 6 = 6

19. Neutron Practice Practice: How many neutrons are in each of the following elements? OxygenChlorineArgonAluminumPhosphorus

20. Atomic Structure Practice Atomic Structure Practice First 25 Elements Activity First 25 Elements Activity

21. Isotopes Isotopes of an element have the same number of protons, but different numbers of neutrons. Isotopes of an element have the same number of protons, but different numbers of neutrons. There can be many isotopes of the same element. There can be many isotopes of the same element.

22. Atom Concept Map

23. Isotopes The average atomic mass of an element is determined by taking a weighted average of all of the isotopes of an element. The average atomic mass of an element is determined by taking a weighted average of all of the isotopes of an element.

24. Isotope Symbols Isotopes of elements have symbols called isotopic symbols: Isotopes of elements have symbols called isotopic symbols: X = Element symbol A = Mass number Z = Atomic number

25. Isotope Symbols The isotope symbol for carbon would be: The isotope symbol for carbon would be: X = Element symbol = C A = Mass number = 12 Z = Atomic number = 6

26. Isotopes of Candium Activity

27. Quick Check What is the atomic number of antimony? What is the atomic number of antimony? What is the symbol for tungsten? What is the symbol for tungsten? How many protons are in tin? How many protons are in tin? How many electrons are in potassium? How many electrons are in potassium? How many neutrons are in phosphorus? How many neutrons are in phosphorus? What is the mass number of lead? What is the mass number of lead?

28. Isotopic Symbol Practice

29. The Bohr Model of the Atom Bohr developed the “planetary” model of the atom, with electrons in orbits around the nucleus. Bohr developed the “planetary” model of the atom, with electrons in orbits around the nucleus. Each of these “orbits”, which we now call shells, is an energy level for electrons. Each of these “orbits”, which we now call shells, is an energy level for electrons. We start by filling the shell closest to the nucleus first We start by filling the shell closest to the nucleus first

30. The Bohr Model of the Atom Each of the shells can only hold a certain number of electrons Each of the shells can only hold a certain number of electrons 1 st shell – maximum 2 electrons 1 st shell – maximum 2 electrons 2 nd shell – maximum 8 electrons 2 nd shell – maximum 8 electrons 3 rd shell – maximum 18 electrons 3 rd shell – maximum 18 electrons Additional shells can hold more, but we do not have to go past the 3 rd shell Additional shells can hold more, but we do not have to go past the 3 rd shell

31. The Bohr Model of the Atom Let’s see what that looks like for hydrogen: Let’s see what that looks like for hydrogen: How many protons? How many electrons? How many neutrons?

32. The Bohr Model of the Atom Let’s see what that looks like for lithium: Let’s see what that looks like for lithium: Build a Bohr Diagram Build a Bohr Diagram Build a Bohr Diagram Build a Bohr Diagram

33. Bohr Model Practice Please do only the following elements on your Bohr Model Worksheet: Please do only the following elements on your Bohr Model Worksheet: SodiumHydrogen CarbonSilicon OxygenChlorine ArgonMagnesium

34. Human Bohr Model Human Bohr Model.avi Human Bohr Model.avi Human Bohr Model.avi Human Bohr Model.avi