Presentation on theme: "1 CHAPTER 2. 2 3 ELEMENTS: Periodic Table ____ total elements : ____ natural and ____ man-made."— Presentation transcript:
1 CHAPTER 2
3 ELEMENTS: Periodic Table ____ total elements : ____ natural and ____ man-made
5 ORGANIZATION OF PERIODIC TABLE
6 ATOMIC STRUCTURE
7 THE NUCLEUS OF AN ATOM How does an atom stay together?
ELECTRON ENERGY LEVELS
9 DIATOMIC ELEMENTS Elements that must exist naturally as 2 atoms bonded together (until it forms a chemical bond with any other element) Br I N Cl H O F H 2 N 2 O 2 F 2 Cl 2 Br 2 I 2
11 CHEMICAL BONDING
Bonding 12 + = Sodium is a silver-colored metal that reacts so violently with water that flames are produced when sodium gets wet. Chlorine is a greenish-colored gas that is so poisonous that it was used as a weapon in World War I. When chemically bonded together, these two dangerous substances form sodium chloride, a compound so safe that we eat it every day - common table salt!
13 Bohr Model Method: Step 1: Draw the energy levels for each element Step 2: Show the arrow of transfer. There should be an arrow showing transfer for EACH electron given away. (Just like the top picture) Step 3: State the ions below each atomic structure to indicate that electrons have been gained or lost. IONIC BOND: Bohr Method
14 IONIC BOND: Lewis Dot Structure NaCl MgO Lewis Dot Method: Step 1: Write the symbol for each atom separately and show valence electrons (evenly spread out ) Step 2: No arrows. Write ions once transfer has taken place. Show electrons for the ORIGINAL outer shell (the one that gained will show electrons). Remember that ions are written as symbol with superscript.
16 COVALENT BOND: Bohr Model Bohr Model Method: Step 1: Draw the energy levels for each element separately. Step 2: Show the energy levels joined (similar to the top picture) All diatomic elements Demonstrate a Covalent bond Remember: BrINClHOF (Chlorine is shown to the right)
17 Molecular formula COVALENT BOND: Lewis Dot Structure Lewis Dot: Step 1: Draw the dot diagram for each element individually (use X and for different atoms) Step 2: Draw the dot diagram for the compound Step 3: Show the molecular formula (including lone electrons)
18 STATES OF MATTER Solid LiquidGas Definite shape Shape of containerNo definite shape Definite volume Volume of containerNo def. volume Tightly packed May overlapVery spread out Vibrate in place Move fasterVery fast
19 CHANGES IN STATE 2 types of Latent Heat = energy absorbed (stored) or released Heat of fusion = energy released; Gas to Liquid to Solid Heat of Vaporization = energy absorbed; Solid to Liquid to Gas
20 CHEMICAL EQUATIONS Reactant Product
22 CHEMICAL REACTIONS Endothermic vs. Exothermic Exothermic– energy released – reactants have more energy than products Endothermic – energy absorbed – products have more energy than reactants
23 SECTION 3 WATER AND SOLUTONS bRONZE brass
24 3 unique characteristics of water
25 POLARITY OF WATER
26 HYDROGEN BONDING (Weak Bond)
Surface Tension is caused by… 27
28 COHESION / ADHESION / CAPILLARITY Cohesion attracts molecules of the same kind (water to water) Adhesion attracts molecules of different kinds (tape and hair) Capillarity is the attraction of molecules allowing a liquid to rise
29 SOLUTIONS bRONZE brass
30 THE DISSOCIATION OF WATER Step 1: One water molecule bumps into another water molecule Step 2: One of the water molecules dissociates (comes apart). When water dissociates, hydroxide ions (OH-) and a hydrogen ion (H+) are produced.
31 ACIDS / BASES Acidity / Alkalinity depends on the amount of hydronium atoms. HCl + NaOH NaCl + H 2 O (Acid) (Base)---(Salt) (Water) If more hydroxide than hydrogen= BASE If hydrogen= hydroxide = NEUTRAL If more hydrogen than hydroxide = ACID