Biology-Ch 4

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  1. What is Chemistry?
    The branch of science that deals with the composition, properties, and change of matter.
  2. What is matter?
    Anything that takes up space and has mass.

    (Composed of one or more elements and not living, but makes up living things.)
  3. What are elements?
    Pure substances that cannot be broken down into other substances by chemical means.
  4. What table arranges elements?
    The Periodic Table arranges elements.
  5. How many elements are there?
  6. What are the 4 most abundant elements in the human body?
    • Oxygen
    • Carbon
    • Hydrogen
    • Nitrogen
  7. Why is iron a trace element?
    Iron only makes up 0.004% (4 one thousandths) of your body mass, but is essential for survival, even in the smallest amounts.
  8. 1. What is anemia?
    2. What are its symptoms?
    3. What foods are remedies for anemia?
    • 1. Not enough iron in your body.
    • 2. Fatigue, pale skin, dizziness, rapid heart rate
    • 3. Red meat, spinach
  9. What is a compound?  Examples?
    Know the difference between an element and a compound.
    • A compound is a substance made up of 2 or more elements that have been combined chemically in a fixed ratio.
    • Ex: Water (H2O), Salt (NaCl)
    • An element is composed of the same type of atoms, where a compound is at least 2 different elements in a fixed ratio.
  10. What is an atom?
    What are an atom's subatomic particles?
    • An atom is the smallest particle of an element.
    • Subatomic particles are:
    • proton (+)
    • neutron (neutral)
    • electron (-)
  11. An element's electron number is the same as _____.
    number of electrons = number of protons

    Positive and Negative forces must balance out.
  12. How is reactivity determined in atoms?
    The variability of electrons (some atoms lose electrons, some gain them).
  13. What are valence electrons?
    The electrons in the outermost shell/energy level of an atom.
  14. If carbon has 6 electrons, how many valence electrons does it have?
    • Carbon has 6 electrons, thus it has 4 in its outer shell (2 in the 1st, 4 in the 2nd).
    • Shell                Max #electrons
    •   1                        2
    •   2                        8 
    •   3                        8
    •   4                      18
    •   5                      18
    •   6                      32
    •   7                      32
  15. The ATOMIC NUMBER of an atom is the same number as the _____.
    number of protons
  16. Know 2 major types of bonds: ionic and covalent, and how they join atoms together.
    • Ionic bonds transfer electrons from one atom to another atom.
    • In Covalent bonds, two atoms share electrons.
  17. Which bond does water have between its 2 hydrogen atoms and 1 oxygen atom?
    Water is a covalent bond because the 2 hydrogens share their electrons with the oxygen atom.
  18. Identify reactants and products in an equation. (Which side of yield arrow sign are each?)
    Reactants (starting materials) ⇒ Products (ending materials)
  19. Water is a polar molecule.  What does this mean?
    Opposite ends have opposite electric charges.
  20. Be able to draw water with its charges and correct name of atoms.
    Image Upload 1
  21. Know how water goes up a tree using cohesion and adhesion.
    • Cohesion (molecules of the same kind stick to one another) keeps water molecules together as they move up towards evaporation in the leaves.
    • Adhesion (molecules of different kinds bind to one another) of the water molecules to the sides of the tree's inner tubes transports to keep gravity from pulling them down.
  22. Acids have lots of _____ ions and bases have lots of _____ ions in them.
    • Acids = lots of H+ ions
    • Bases = lots of OH- ions
  23. Be able to balance an equation.
    • Image Upload 2
    • ___Al + ___O2 ⇒ ___Al2O3
    • 4Al + 3O2 = 2Al2O3
  24. Know the pH scale.
    Which side is increasing acidity and which side is increasing alkalinity (basic)?
    Image Upload 3
Card Set
Biology-Ch 4
Biology first semester review chapter 4
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