5.2 The Periodic Table

…the periodic table is organized to make sense out of the elements…

An Organized Table • The periodic table is organized into rows and columns. • Rows: The atomic number (number of protons) increases by one. Rows are called periods. • Columns: These elements share similar valence electron arrangements. Columns are called groups.

As you go from → the number of protons increases by 1. Columns: These elements share similar valence electron arrangements.

All elements in the 1st column have 1 valence electron.

All elements in the 2nd column have 2 valence electrons Number of Electrons in the Orbitals (Levels) • Each orbital holds a different number of electrons. • Here they are:

• 1st holds up to 2 • 2nd holds up to 8 • 3rd holds up to 18 • 4th holds up to 32 Bohr’s Model

• According to Bohr’s model of the atom, electrons behave like planets orbiting the sun. 4.2 Atomic Structure

…atomic numbers, atomic mass numbers, and isotopes… Atomic Numbers • The atomic number of an atom is the number of protons and electrons it has.

Silver always has an atomic number of 47 Atomic Mass Number • The total number of protons and neutrons in an atom is the atomic mass number. • Subtract the mass number by the number of protons to find the number of neutrons.

To find atomic mass, add up the protons and neutrons.

6 Protons +6 Neutrons 12 Atomic Mass Carbon-12 Atomic Structure

• Nucleus is the center of an atom. • The protons and neutrons are located in the nucleus. • The electron cloud is the outer part of the atom. • Electrons are located in the electron cloud. • Electrons circle the nucleus in orbital's just like the planets circle the sun. How do I find the number of protons, electrons, and neutrons in an element using the periodic table? o# of PROTONS = ATOMIC NUMBER o# of ELECTRONS = ATOMIC NUMBER

o# of NEUTRONS = ATOMIC MASS - ATOMIC NUMBER How do you read the PERIODIC TABLE?

What is Nuclear Radiation?

• https://www.youtube.com/watch?v=Zw0pHT47AAU&feature=youtu. be The Periodic Table E- Learning Answer the following questions. 1.The periodic table is organized into _____ and ______. 2.How many periods are there on the periodic table of elements? 3. How many groups are there on the Periodic table of elements? 4. What is the atomic number of tin? 5. What is the symbol for Lead? 6. How many protons does this element have? 7. How many electrons does this element have? 8. How many neutrons does Krypton have? 9. Label the 4 parts: 10. How do you find the number of neutrons? 11. Each orbital holds a different number of electrons, what are they? • 1st holds up to ___ • 2nd holds up to ___ • 3rd holds up to ___ • 4th holds up to ___ 12. Draw the atom Sodium? 13. What did Bohr’s Model say? 14. How many neutrons are in Gallium? 15. Rows are called______. 16. Columns are called ______. Are the pink & yellow columns/groups or periods? There are 3 things missing, fill them in. 17. What does, 2,8, 4 represent? 18. Nucleus is the center of an ______. • Andrew • Adam • Alex • Atom • Amanda 19. Electrons are located where?