Biology Chapter 2

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Biology Chapter 2
2014-09-22 19:27:03
Biology Chapter
Biology Chapter 2
Biology Chapter 2
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  1. What is an Organic Compound?
    Always contains Carbon
  2. What is the Atomic Nucleus?
    the central core of an atom, composed of protons and neutrons, constituting most of its mass but only a small part of its volume
  3. What is atomic mass?
    atomic weight; used particularly when describing a single isotope of a nuclide.
  4. What is the Atomic Number?
    ) a number expressive of the number of protons in an atomic nucleus
  5. What is an element?
    A substance that cannot be reduced to simpler substances by normal chemical means and that is composed of atoms having an identicalnumber of protons in each nucleus.
  6. What is an isotope?
    Different forms of the same element with the same number of protons but different numbers of neutrons.
  7. What is a neutron?
    an electrically neutral or uncharged particle of matter existing along with protons in the nucleus of atoms of allelements except the mass 1 isotope of hydrogen. Symbol n.
  8. What is a Radio Isotope?
    An isotope that is unstable and undergoes radioactive decay, releasing energy.
  9. What is a Chemical Compound?
    in chemistry, a substance consisting of two or more elements in union
  10. What is a Molecule?
    The smallest particle into which an element or a compound can be divided without changing its chemical and physical properties; a group of atoms that is held together chemically.
  11. What is Structural Formula?
    a chemical formula showing the number of atoms of each element in a molecule, their spatial arrangement, and their linkageto each other.
  12. What is Chemical Formula?
    combination of symbols used to express the chemical composition of a substance.
  13. What is molecular formula?
    a chemical formula expressing the number of atoms of each element present in a molecule of a substance, without indicating how they are linked.
  14. What is a Mole?
    weight of a substance in grams that corresponds to the atomic masses of all the component atoms in a molecule of that substance. One mole of a compound always contains 6.023 ×1023molecules.
  15. What is molecular mass?
    he mass of a molecule in daltons, derived by addition of the component atomic masses. Its dimensionless equivalent is molecularweight.
  16. What is Avogrado's number?
    • The number of molecules in a mole of a substance, approximately 6.0225 × 1023. Also called Avogadro's constant.
  17. What is a Reactant?
    A substance participating in a chemical reaction, especially a directly reacting substance present at the start of the reaction.
  18. What is Dynamic Equilibrium?
    the condition of balance between varying, shifting, and opposing forces that is characteristic of living processes.
  19. What is a chemical bond?
    The linkage or force holding two neighboring atoms of a molecule in place and resisting their separation, usually accomplished by the transferor sharing of one or more electrons or pairs of electrons between the atoms.
  20. What is a Covalent Bond?
    a chemical bond between two atoms or radicals formed by the sharing of a pair (single bond), two pairs (double bond), or three pairs of electrons (triple bond).
  21. What is a Polar Covalent bond?
    A covalent bond in which electrons are shared unequally due to differences in electronegativity of the atoms involved. One atom has a partial negative charge and the other a partial positive charge, even though the molecule is electrically neutral overall.
  22. What's a Nonpolar molecule?
    one that the electrons are distributed more symmetrically and thus does not have an abundance of charges at the opposite sides. The charges all cancel out each other.
  23. What is a Polar Molecule?
    a molecule in which the centroid of the positive charges is different from the centroid of the negative charges.
  24. What is an Ion?
    an electrically charged atom or group of atoms formed by the loss or gain of one or more electrons, as a cation (positive ion) which is created by electron loss and is attracted to the cathode in electrolysis,or as an anion (negative ion) which is created by an electron gain and is attracted to the anode. The valence of an ion is equal to the number of electrons lost or gained and is indicated by a plus sign forcations and a minus sign for anions, thus: Na +, Cl−, Ca ++, S =.
  25. What is an Ionic bond?
    the electrostatic bond between two ions formed through the transfer of one or more electrons.
  26. What is a Solute?
    the substance dissolved in a given solution.
  27. What is a Hydration Reaction?
    A hydration reaction is a reaction where a hydrogen and hydroxyl ion is attached to a carbon in a carbon double bond.
  28. What is a Hydrogen Bond?
    A weak association formed with hydrogen in polar covalent bonds. The partially positive hydrogen is attracted to partially negative atoms in polar covalent bonds. In water, oxygen and hydrogen in different water molecules form hydrogen bonds.
  29. What is Cohesion?
    Cohesion is the attractive force between like molecules.Cohesion is the measure of how well molecules 'stick' or group together to themselves.
  30. What is Adhesion?
    the tendency of dissimilar particles or surfaces to cling to one another (cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The forces that cause adhesion and cohesion can be divided into several types
  31. What is Capillary Action?
    the process involving molecular adhesion by which the surface of a liquid in a tube is either elevated or depressed, depending on the cohesiveness of the liquid molecules. The more cohesive the molecules, the more depressed will be the surface of the liquid. Less cohesive liquid molecules will adhere to the surfaces of the tube in which they are contained and elevate the surface of the liquid.
  32. What is Kinetic Energy?
    energy of motion
  33. What is Heat?
    Heat is the form of energy that flows between two samples of matter due to their difference in temperature .
  34. What is Specific Heat?
    the heat required to raise the temperature of the unit mass of a given substance by a given amount (usually one degree).
  35. What is a Calorie?
    The amount of heat required to raise the temperature of one gram of water from 14.5°C to 15.5°C. 1 calorie = 4.184 joules.
  36. What is a Buffer?
    is an aqueous solution that has a highly stable pH . If you add acidor base to a buffered solution, its pH will not change significantly. Similarly, adding water to a buffer or allowing water to evaporate will not change the pH of a buffer.
  37. Yes