The Periodic Table and its Organization

1. Chapter 18 Lesson 3 Part The Periodic Table

2. Dmitri Mendeleev Dmitri Mendeleev (1869, Russian) Organized elements by increasing atomic mass. Predicted the existence of undiscovered elements.

3. Henry Mosely Henry Mosely (1913, British) Organized elements by increasing atomic number. One proton and electron are added to each element as you go across the table. Fixed problems in Mendeleev’s arrangement.

4. Metals • Nonmetals • Metalloids Metallic Character

5. Metallic Character Metals- good conductors of heat and electricity, Malleable (most metals can be hammered into thin sheets) Nonmetals- gases that are poor conductors of heat and electricity at room temperature, Brittle (breaks easily) Metalloids- Conduct heat and electricity better than nonmetals but not as well as metals, Can be shiny or dull , Solids

6. Representative Elements • Transition Metals • Inner Transition Metals Table Sections

7. Lanthanides - part of period 6 Actinides - part of period 7 Table Sections Overall Configuration

8. Group (Family) • Period 1 18 Columns & Rows 1 2 14 13 15 16 17 2 3 3 4 8 5 6 7 9 10 11 12 4 5 6 7

9. Terms Periodic Law Properties of elements repeat periodically when the elements are arranged by increasing atomic number. Moving from left to right in a row of the periodic table, metallic properties decrease.

10. Terms Valence Electrons e- in the outermost energy level Atomic Radius First Ionization Energy energy required to remove an e- from a neutral atom

11. Periodic Trends Atomic Radius Increases to the LEFT and DOWN

12. Periodic Trends First Ionization Energy Increases to the RIGHT and UP

13. 1A 8A 2A 3A 4A 5A 6A 7A Periodic Trends Group # = # of valence e- (except He) Families have similar reactivity. Period # = # of energy levels

14. Orbital Region where there is 90% probability of finding an electron. Can’t pinpoint the location of an electron Density of dots represents degree of probability.

15. Orbital Orbitals have different shapes

16. EnergyLevels Electrons can only exist at certain energy levels. Low energy levels are close to the nucleus. Each energy level (n) can hold 2n2 electrons.

17. Can replace with: 3p 4n p n n n p p n Bohr Model Diagrams e- Simplified energy levels using Bohr’s idea of circular orbits. Lithium Atomic #: 3 Mass: 7 # of p: 3 # of e: 3 # of n: 4 e- Maximum e- Level 1 2e- Level 2 8e- Level 3 18e- Level 4 32e- e-

18. Bohr Model Activity Choose a number between 1 & 50. Find your element by the atomic number you picked. Make a Bohr Model diagram for your element on a piece of cardstock (make sure you put your name on it because you will be turning it in for a grade). Round off the mass listed on the table and subtract the atomic # to find the # of neutrons. Abbreviate the # of ‘p’ and ‘n’ in the nucleus. I have the card stock, yarn, and electrons, protons and neutrons (cereal)