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Basic chemistry Why learn it? Life depends on chemistry. If the first task of an architect is to understand building materials, then the first job of a.

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Presentation on theme: "Basic chemistry Why learn it? Life depends on chemistry. If the first task of an architect is to understand building materials, then the first job of a."— Presentation transcript:

1 Basic chemistry Why learn it? Life depends on chemistry. If the first task of an architect is to understand building materials, then the first job of a biologist is to understand the chemistry of life. Where? Chapter 2 of your textbook

2 What? In order: 1.The basics: Atoms and Compounds (small) 2.Properties of Water 3.Macromolecules (big) 4.Enzymes: how they get things done I anticipate a number of lab activities, at least 1 project, and 1 vocab assignment. There will also be some small homework assignments.

3 Atoms Atoms – The basic unit of matter. Atoms are very small, made up of subatomic particles that are even smaller than the atom. Atoms are usually neutral, meaning they have no charge.

4 Protons Protons-  Have about the same mass as a neutron.  Have a positive charge  Contained in nucleus in the center of the atom Atoms have the same number of protons as electrons

5 Neutrons  Have about the same mass as a proton.  Have no charge = neutral Contained in nucleus in the center of the atom

6 Electrons  Negatively charged particle  Electrons are in constant motion  They move around the out side of the nucleus  Atoms have the same number of protons as electrons  Electrons are in orbits around the nucleus  The first orbit can hold 2 electrons The second orbit can hold up to eight electrons

7 Element Element-  is a substance composed of only one type of atom  more than 100 elements  Elements are represented by one or two letter symbol Sum of protons and neutrons in nucleus is called atomic mass

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9 Periodic Table Atomic Number - Simply refers to the number of protons present in the atom. Element Symbol - This is the symbol that chemical formulas or equations use to indicate that certain element. Atomic Mass - The average mass of one atom of that element in amu's (Atomic Mass Units).

10 Compounds Chemical compounds  Substance formed by two or more elements  Formed in definite proportions  Properties of compound is different that the elements its formed by  Hydrogen and oxygen are gases at room temperature, when combined they form water, a liquid, at room temperature.

11 Bonding Chemical Bonds-  Atoms in a compound are held together by chemical bonds  Bonds are formed by the electrons in the area around the nucleus The electrons that are available to from bonds are called valence electrons

12 Bonding Covalent bonds  Strongest bonds  Shared electrons

13 Two electrons are shared Single covalent Bond

14  Double covalent bond Four electrons are shared

15 Ions  Ions are formed by giving up or receiving an electron  Ions can have a positive charge or negative charge  If atom gives an electron it has a positive charge called a Cation If atom gains an electron it has an negative charge called an Anion

16 Ionic Bonds  Formed when one or more electrons are transferred from one atom to the other

17 Isotopes Isotopes-  Have different number of neutrons  They have the same number of electrons & protons All chemical properties such as bonding remain the same

18 Van der Waals Forces  Not all electrons are shared equally when bonds are formed  When sharing is unequal, one end of a molecule may be slightly more positive or negative than the other  A slight attraction between molecules can develop because of oppositely charged regions

19 Van der Waals forces


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