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Chapter 2: Chemistry What is matter made up of and how does it react?

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Presentation on theme: "Chapter 2: Chemistry What is matter made up of and how does it react?"— Presentation transcript:

1 Chapter 2: Chemistry What is matter made up of and how does it react?

2 What is Matter? Anything that occupies space and has mass.

3 Elements Pure substance made up of only one kind of atom 90 occur naturally 25 essential to life: O, C, H, N –0= 65%, C=18.5%, H=9.5%, N=3.2% Atom: smallest unit of matter that cannot be broken down by chemical means.

4 Periodic Table Atomic Symbol: C = carbon, or Au = gold Atomic Number: Number of Protons in an Atom. Carbon has ? Gold has ? Atomic Mass: Number of Protons and Neutrons. Isotope: Different numbers of Neutrons than Protons Periodic Table

5 Atoms Three major parts. –Protons: Positive Charge. Inside Nucleus –Neutrons : Neutral Charge. Inside Nucleus: –Electrons: Negative Charge. Outside Nucleus 2 electrons in first shell 8 electrons in the second shell Eight is Great! Will not React with other atoms. If the outer shell is not full it will react.

6 Combining Chemicals Compound: When two or more different elements combine. Hydrogen Bond: H 2 O –When hydrogen bonds with another atom. Creates a polar molecule. Covalent bond: CO 2 –When atoms on the same side of the chart (same size) bond. Share electrons. Both Hydrogen and Covalent bonds form molecules, ionic bonds do not. Ionic/ Covalent Bonds Periodic Table Bonding

7 Combining Chemicals continued Ionic Bonds: When atoms on different sides of the chart (different size) bond. Steal electrons. Create Ions. Make teeth and bones. Ion: Charged particle either negative or positive. NaCl = table salt Free Radical: Electrically charged ion with an unpaired electron in its outer shell.

8 Antioxidants, What are they? Subatances that inactivate oxygenderived free-radicals Slows damage from free-radicals Examples: Selenium, Zinc Beta-carotene, Viamins C & E Acai Berry Free Radicals

9 Energy and Chemical Reactions Reactants and Products –Co 2 + H 2 0 = H 2 C0 3 Energy Transfer –Exergonic Rxns- Energy exits or released –Endergonic Rxns- Net absorption of energy Activation energy –Energy needed to start the reaction. Catalysts reduce the energy needed. Often enzymes.

10 More on Ionic Bonds Ionic Bonds have 2 parts –Cation: Positively Charge, Ca+2 Has lost 2 electrons –Anion: Negatively Charged, Cl- Has Gained to electrons Electrolytes: Ionic compounds that breaak into cations and anions when dissolved. (Salt)

11 Solution A mixture in which one or more substances are evenly distributed in another substance. Solute: smaller word, smaller thing Solvent: bigger word, bigger thing

12 The Importance of Water Polar molecule (it has a negative and positive charge.) –Can dissolve both Ionic and Polar-Covalent molecules Surface Tension –Cohesion: Sticks to itself. –Adhesion: Like a band-aid. Sticks to stuff Capillary Action: Climbs up thin tubes Importance of Water: an inorganic compound

13 Evaporates: Cooling, Water cycle, etc Resists Temperature Change: Takes a lot of energy to heat or cool water Expands as it Freezes.

14 Ph Scale Measured on grams of Hydrogen (H+) –pH of 1= 1g of H+, pH of 2=.01g of H+ Acid: form hydronium ions (H+) –pH of less than 7 ( 1 to 6.9) Base: form hydroxide ions (OH-) –pH of more than 7 (7.1 to 14) Acid + Base: salt & water, the solution is neutral with a pH of 7. –NaOH + HCL = H 2 O + NaCl with a pH of 7

15 What is a Buffer? Chemical substances that neutralizes small amounts of an acid or base added to a solution. Why are these important to your body?

16 Organic Compounds: C-H Carbohydrate: fast energy –made of Carbon, Hydrogen, and Oxygen. 1:2:1 proportion. Sacchar = sugar Monosaccharides:C6H12O6, glucose and fructose Disaccharides: 2 sacchar’s: Sucrose, table sugar Polysaccharides: Many sacchar’s: Cellulose (wood) and starch. Carbohydrates

17 Organic Compounds: C-H Lipids: Fats long term energy storage –Have very few oxygen atoms –Saturated fats: All C bonded to H. Lard, and butter. –Unsaturated fats: C is double bonded to itself. Oil. Lipids

18 Organic Compounds: All organic compounds contain Carbon. Protein: the working molecule –50 or more Amino Acids make a protein –Types of Proteins Muscle Enzymes: Control chemical reactions and can be re-used like a key in a lock Hair Protein

19 Organic Compounds: All organic compounds contain Carbon. Nucleic Acids: pg. 37 DNA and RNA –Made of nucleotides: Sugar, Phosphate, and X ATP: energy cells run on. DNA


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