AP Biology Chapter 2 and 26 Guided Reading Assignment
1. An Element is a substance that cannot be broken down to other substances by chemical reactions, while a compound is a substance consisting of two or more different elements combined in a fixed ratio.
Area around the nucleus where electrons are likely to be found.
Electron: particle with a negative charge
Neutron: a subatomic particle with no charge
Electron shell: the energy level where electrons are likely to be found.
Proton: subatomic particles with a positive charge.
Nucleus: protons and neutrons are located in the center of the atom
3. Atomic mass is an approximation of the total mass of an atom, which is the total number of protons and neutrons. The atomic number is the number of protons.
4. The difference between the terms atomic mass and atomic weight is that atomic mass is the average mass of all an elements isotopes while the atomic weight is the actual weight of an isotope.
5. An isotope is an atom containing different numbers of neutrons, differing in atomic mass. Basically an atom with a different atomic mass. What’s special about radioactive isotopes is that a radioactive isotope has a nucleus that decays spontaneously giving off particles and energy.
6. Radioactive tracers are used in science to label certain chemical substances, so metabolic processes can be followed and substances can be located in an organism. Radioactive tracers are important diagnostic tools in medicine.
7. The movement of electrons relates to the concept of potential energy because the farther an electron is from the nucleus the more energy it has. The farther an object is from the ground the more potential energy it has.
8. What determines interactions between atoms is the number of valence electrons. Valence electrons are important because the chemical behavior of an atom depends on it.
9. Chemical Bond: an attraction between two atoms resulting from a sharing of outer shell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells. Covalent Bond: a type of strong chemical bond in which two atoms share one or more pairs of valence electrons. Single Bond: the sharing of one pair of electrons between two atoms. Double Bond: the sharing of two pairs of electrons between two atoms. Valence: the bonding capacity of an atom, generally equal to the number of unpaired electrons in the atoms outermost shell. Electronegativity: the attraction of an atom for the electrons of a covalent bond. Nonpolar Covalent Bond: A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity. Polar Covalent Bond: A covalent bond between atoms that differ in Electronegativity. The shared electrons are pulled closer to the more electronegative atom making it slightly negative and the other atom slightly positive.
10. The difference between structural and molecular formula is that the molecular formula writes the chemical symbol with subscripts while the formula indicates bonds.
11. Ionic bonds compare with covalent bonds, because covalent bonds are stronger that ionic bonds. Ionic bonds are formed by the attraction of an anion and a cation. A covalent bond is formed by the sharing of valence electrons.
12. Hydrogen bonds are interactions between positive poles and negative poles of polar molecules for example like water. Van der Waals interactions are between the positive nucleus of one atom and the negative electron cloud of neighboring atoms.
13. An example in a loving system of how molecular shape is critical is that molecular shape determines the function of a molecule. If something changes the shape of a molecule it will no longer function properly.
14. The definition of a dynamic chemical equilibrium in terms of quantities of reactants and products is that in a...
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