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Advanced Placement Biology. Mr. Jim Sullivan Boston University. Boston University Project STAMP. STAMP S ciecne, T echnology, A nd M ath P artnerships. Undergraduate- Boston College Study of Painted Turtles. Past: Undergraduate- Boston College Study of Painted Turtles.
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Advanced Placement Biology Mr. Jim Sullivan Boston University
Boston University Project STAMP • STAMP • Sciecne, Technology, And Math Partnerships
Past:‘Radio’-pharmaceuticals • Using ‘radioactive’ chemicals to create therapeutic medicines • Designed to fight cancer
Boston University Ecology Molecular Biology Environmental Chemistry You! Working with you guys. Exploring and understanding biology from the molecular to the organismal level Present: Nematostella vectensis
Time for the flashlight! • Before going into Genetics, we need to review basic chemistry
Time for the flashlight! • Before going into Genetics, we need to review basic chemistry • Why is Chemistry important for understanding biology?
What are atoms comprised of? • Neutrons, Protons, and Electrons • Neutrons • Electrically neutral • Found in nucleus • Have mass • Protons • Positively charged • Found in nucleus • Have mass • Electrons • Negatively charged • Encircle the nucleus • Do not have mass Contains protons and protons
Define Mass • Mass is an important unit of measurement which will come up often throughout the year. • Mass is a measure of ‘matter.’ • It is a function of both the density and the size of the object in question. • Are mass and weight identical?
How do we describe atoms? • We define different atoms based upon the number of each of their three components. • What are the three parts of an atom again?
How do we describe atoms? • We define different atoms based upon the number of each of their three components. • Neutrons, Protons, and Electrons • Each atom has a unique number of protons. • Atoms are (usually) electrically neutral, so the number of electrons equals the number of protons. • The atomic mass describes the sum of protons and neutrons
How Do We Differentiate Between Atoms? • Tell me how many neutrons, protons, and electrons are in the following elements 1632S 15 30P 816O 714N 612C 11H
How Do We Differentiate Between Atoms? • Tell me how many neutrons, protons, and electrons are in the following elements • 16 protons, 16 neutrons, 16 e- 1632S 15 30P 816O 714N 612C 11H
How Do We Differentiate Between Atoms? • Tell me how many neutrons, protons, and electrons are in the following elements • 16 protons, 16 neutrons, 16 e- 1632S • 15 protons, 15 neutrons, 15 e- 15 30P 816O 714N 612C 11H
How Do We Differentiate Between Atoms? • Tell me how many neutrons, protons, and electrons are in the following elements • 16 protons, 16 neutrons, 16 e- 1632S • 15 protons, 15 neutrons, 15 e- 15 30P • 8 protons, 8 neutrons, 8 e- 816O 714N 612C 11H
How Do We Differentiate Between Atoms? • Tell me how many neutrons, protons, and electrons are in the following elements • 16 protons, 16 neutrons, 16 e- 1632S • 15 protons, 15 neutrons, 15 e- 15 30P • 8 protons, 8 neutrons, 8 e- 816O • 7 protons, 7 neutrons, 7 e- 714N 612C 11H
How Do We Differentiate Between Atoms? • Tell me how many neutrons, protons, and electrons are in the following elements • 16 protons, 16 neutrons, 16 e- 1632S • 15 protons, 15 neutrons, 15 e- 15 30P • 8 protons, 8 neutrons, 8 e- 816O • 7 protons, 7 neutrons, 7 e- 714N • 6 protons, 6 neutrons, 6 e- 612C 11H
How Do We Differentiate Between Atoms? • Tell me how many neutrons, protons, and electrons are in the following elements • 16 protons, 16 neutrons, 16 e- 1632S • 15 protons, 15 neutrons, 15 e- 15 30P 816O • 8 protons, 8 neutrons, 8 e- • 7 protons, 7 neutrons, 7 e- 714N • 6 protons, 6 neutrons, 6 e- 612C 11H • 1 proton, 0 neutrons, 1 e-
How Do We Differentiate Between Atoms? • Tell me how many neutrons, protons, and electrons are in the following elements Sulfur 1632 S • These 6 elements, which you can remember as ‘SPONCH’ make up • 97.6% of your body, by mass 15 30 P Phosphorous 816 O Oxygen 714 N Nitrogen Carbon 612 C Hydrogen 11 H
How Do We Differentiate Between Atoms? • Tell me how many neutrons, protons, and electrons are in the following elements 1632 S • Two other essential elements are • Calcium (Ca) and Iron (Fe), which you • remember as ‘CaFE.’ • Using your Periodic Table, tell me how • neutrons, protons, and electrons are • present in atoms of these elements 15 30 P 816 O 714 N 612 C 11 H
Bonds • What is a bond?
Bonds • What is a bond? • A bond between atoms is the result of interactions bringing atoms closer together • Name different types of bonds
Types of Bonds • There are four types of bonds that will be important to us throughout the year: • Ionic Bonds • Covalent Bonds • Hydrogen Bonds • van der Waals Interactions • For now, you should understand Ionic and Covalent bonds, we’ll cover the others later
Ionic and Covalent Bonds • These bonds are interactions between atoms in which each of the atoms involved attempts to fill its valence shell with eight electrons • In ionic bonds, there is taking and giving of electrons • In covalent bonds, there is a sharing of electrons
Ionic Bonds- The Bully • Look for the ‘electronegativity (δ)’ section of your periodic table. • This number indicates how strongly electrons are drawn to the nucleus of that particular atom; the higher the number, the greater the affinity • If the difference of electronegativities (δ) of atoms which share a bond is ≥ 1.5, then the bond is ionic • The more electronegative atom involved ‘takes’ the electrons from the less electronegative
Covalent Bonds- Friendly Atoms • If the difference between electronegativities (δ) of atoms sharing a bond is < 1.5, then the atoms in the bond are sharing the electrons • These are Covalent Bonds
Just to confuse you… • There are two types of covalent bonds • Non-polar • Polar
Just to confuse you… • There are two types of covalent bonds • Non-polar • Polar • In Non-polar Covalent bonds, the electrons are shared almost completely equally • CH4 is an example • The difference in terms of δ between C and H is 2.6 - 2.2 = 0.4 H C H H H
Just to confuse you… • There are two types of covalent bonds • Non-polar • Polar • In Polar Covalent Bonds, the electrons are still shared… • but not as equally. H2O is an example • The difference in electronegativities (δ) between O (3.4) • and H (2.2) is 3.4 – 2.2 =1.2 • This is still a covalent bond, but one in which electrons are • not evenly shared • The polar nature of water gives it unique properties!
Ionic or Covalent? NaCl
Ionic or Covalent? NaCl- Ionic (3.2 - 0.9 = 2.3) Table Salt N2
Ionic or Covalent? NaCl- Ionic (3.2 - 0.9 = 2.3) Table Salt N2- Covalent (3.0 – 3.0 = 0) Dinitrogen gas, makes up ~78% of the air we breathe CH4
Ionic or Covalent? NaCl- Ionic (3.2 - 0.9 = 2.3) Table Salt N2- Covalent (3.0 – 3.0 = 0) Dinitrogen gas, makes up ~78% of the air we breathe CH4- Covalent (2.6 – 2.2 =0.4) Methane, aka Natural Gas HF
Ionic or Covalent? NaCl- Ionic (3.2 - 0.9 = 2.3) Table Salt N2- Covalent (3.0 – 3.0 = 0) Dinitrogen gas, makes up ~78% of the air we breathe CH4- Covalent (2.6 – 2.2 =0.4) Methane, aka Natural Gas HF- Ionic (4.0 – 2.2 = 1.8) Hydrogen flouride
Review • What are the three components of an atom?
Review • What are the three components of an atom? • How can we interpret the periodic table. • Write down the number of protons, electrons, and neutrons for five elements. Write down the electronegativity of each also.
Review • What are the three components of an atom? • How can we interpret the periodic table. • Write down the number of protons, electrons, and neutrons for five elements. Write down the electronegativity of each also. • What is a bond? • Name four types of bonds
Review • What are the three components of an atom? • How can we interpret the periodic table. • Write down the number of protons, electrons, and neutrons for five elements. Write down the electronegativity of each also. • What is a bond? • Name four types of bonds • What is the difference between an ionic and a covalent bond?
Review • What are the three components of an atom? • How can we interpret the periodic table. • Write down the number of protons, electrons, and neutrons for five elements. Write down the electronegativity of each also. • What is a bond? • Name four types of bonds • What is the difference between an ionic and a covalent bond? • What are the two types of covalent bonds?