i. chemistry. a. elements and atoms 1. elements- substance which cannot be broken down into a...
TRANSCRIPT
![Page 1: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/1.jpg)
I. Chemistry
![Page 2: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/2.jpg)
A. Elements and Atoms
1. Elements- Substance which cannot be broken down into a simpler substance
A) 96% of all life is Carbon, Hydrogen, oxygen and nitrogen
B) 3.2% Calcium, Phosphorous, Potassium and Sulfur
![Page 3: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/3.jpg)
2. Atom- The smallest particle of an elementa) Atomic structure
1. Proton- positively charged. In nucleus. 1 Dalton mass
2. Neutron- neutral charge. In nucleus. 1 Dalton mass
3. Electron- negative charge. Orbits nucleus. 1/2000 Dalton mass
![Page 4: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/4.jpg)
b) Electron Energy Levels
Energy Level Maximum Number of Electrons
1st (K)
2nd (L)
3rd (M)
4th (N)
2) However, the outer energy level: the valence shell will never hold more than 8 electrons
1)
2 electrons
8 electrons
18 electrons
32 electrons
![Page 5: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/5.jpg)
3. Periodic Table- Chart of Elements arranged by proton number and valence electrons
8
OOxygen
15.9
e) Neutron Number = Atomic mass – Atomic number
a) Atomic Number- indicates the number of proton(s) which determines the identity of the element
b) Symbol- Identifies the element
c) Atomic Mass- the mass of the atom in Daltons.
d) Atoms are Neutral- Therefore the number of proton and electrons are equal
![Page 6: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/6.jpg)
4. Bohr Diagrams- illustrations of an atom. Example: Oxygen
8p
8n
6e2e
5. Isotopes- Atoms with extra neutrons. Some are unstable and give off radiation as they decay
Number of electrons in 2nd energy level
Electrons in the first energy level
Nucleus with the number of protons in & neutrons
![Page 7: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/7.jpg)
B. Chemical Bonding
1. Compound- two or more elements chemically combined
2. Molecule- smallest particle of a compound
H2O 2CO2 C2H5OH C6H12O6
Atoms
Elements
Molecules
3
2 2 3
9
1
6
2 1 1
24
3
![Page 8: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/8.jpg)
What Determines Whether Atoms Bond?
3. Atoms with their outer energy level filled are stable. He, Ne, Ar, Kr, Xe, Rn (Noble Gasses). Keep in mind that helium’s first energy level is its outer energy level and therefore requires only two electrons in its valence shell for stability
4. Unstable atoms will share or transfer electrons to become stable
![Page 9: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/9.jpg)
C. Covalent Bonding- Sharing a pair of electrons to fill the outer energy level
p
p
P8
n8
2e-
e-
e-
e-
e-
e-
e-
OxygenHydrogen
Hydrogen
e-
e-
![Page 10: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/10.jpg)
Example of Ionic Bonding
Valence Electrons =Sodium’s Electronegativity =
Valence Electrons =Chlorine’s Electronegativity =
Electron Transfer
1 7
0.93 3.16
Electronegativity Difference = 2.23 > 1.67
Attraction
Sodium
Atom AtomChlorine
Ion Ion
![Page 11: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/11.jpg)
D. Ionic Bonding- The transfer of electrons from one element to another to fill the outer energy level
1. Electronegativity- a measure of the attraction of electrons to an atom.
2. When atoms with high electrogenativities are placed with atoms with low electronegativities (the difference is greater than 1.67), Ionic bonding occurs
a) The transfer of the electron from one atom to another causes the formation of particles called ions
b) Ions with opposite charges attract
![Page 12: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/12.jpg)
E. Hydrogen Bonds- weak bonds between polar molecules
1. When atoms with different electronegativites covalently bond, electrons are shared unequally resulting in polar covalent bonds.
2. Hydrogen bonds can then for between the molecules or even parts of large molecules like DNA and proteins
![Page 13: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/13.jpg)
“Many have lived a life without love, not one without water.”
![Page 14: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/14.jpg)
F. Water’s Importance to Life
1. All living things contain a large amount of water. Ex. Humans are 60-65% water
2. Living things are essentially water solutions
A) Solution- a solute dissolved in a solventB) Concentration- the amount of solute in the
solventC) Solutions are mixtures. The solute and the
solvent do not chemically combine
![Page 15: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/15.jpg)
3. The Properties of Water
![Page 16: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/16.jpg)
a. Cohesion- water molecules cling to each other. This aids in the transport of water in plants
![Page 17: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/17.jpg)
Adhesion
b. Adhesion- water molecules cling to other substances. Aids in the transport of water in plants
![Page 18: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/18.jpg)
c. High Heat Capacity- water resists changes in temperature. Moderates global temperatures
![Page 19: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/19.jpg)
d. Water Expands when it Freezes- ice is less dense than liquid water. Insulates water in winter keeping it in liquid form
![Page 20: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/20.jpg)
e. Water is an excellent solvent most substances dissolve in water. Allows for nutrient transportation in organisms
![Page 21: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/21.jpg)
f. Water is clear- this allows light to penetrate to aquatic plants
![Page 22: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/22.jpg)
G. Acids, Bases and pH
1. Acids- release H+ ions (hydrogen ions) in solution
2. Base- release OH- ions (Hydroxide ion) in solution
3. pH Scale- measure of the H+ ions in a solution
![Page 23: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/23.jpg)
Acids, Bases and pH1. Dissociation of water molecules (H2O H+ +
OH-) is a rare occurrence. Only one molecule of water is disassociated per 554 million water molecules.
2. Thus, at 25oC, the number of hydrogen ions (H+) and hydroxide ions (OH-) is equal at 10-7 M.
3. In any solution, the sum of the OH- ions and H+ ions is 10-14
4. The concentrations of hydrogen ions and hydroxide ions are exactly inverse! Increase one and you will decrease the other.
5. The pH scale is based on the power of 10
![Page 24: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/24.jpg)
You Try a Problem
If an acid was added to water to increase the hydrogen ion concentration to 10-5, what would be the hydroxide ion concentration? What would be the pH?
If base was added to a solution until the hydroxide ion concentration was 10-3, what would be the hydrogen ion concentration? What would be the pH?
If the pH of a solution is 6, what is the hydrogen ion concentration? What is the hydroxide ion concentration?
![Page 25: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/25.jpg)
H. Chemical Reactions- breaking of existing bonds and the formation of
new ones
1. Activation Energy- energy needed to start a reaction. (heat, stirring, electric.)
2. Atoms cannot be created or destroyed in a chemical reaction, they are only rearranged into different molecules
![Page 26: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/26.jpg)
3. Example: H2 + O2 H2O
Reactants yields Products
2H2 + O2 2 H20
coefficient
Subscript
![Page 27: I. Chemistry. A. Elements and Atoms 1. Elements- Substance which cannot be broken down into a simpler substance A) 96% of all life is Carbon, Hydrogen,](https://reader030.vdocument.in/reader030/viewer/2022032313/56649e665503460f94b61e75/html5/thumbnails/27.jpg)
4. Endergonic Vs Exergonic Reactions