Notes Chapter 2 Chemistry of Life
I.
Nature of Matter
a. Matter is made of Atoms
i. All matter consists of _________. An __________ is the smallest unit of matter that cannot be
broken down by chemical means.
ii. The three particles of an atom are the _________________, _____________________, and
____________________________.
b. Elements are the simplest pure substances.
i. An ______________ is a substance made of only one kind of _______, and it is therefore a pure
substance.
ii. There are over _____ known elements.
iii. Examples of elements are ________ and ___________.
iv. Elements differ in the number of ______________ their elements contain.
c. Atoms can bond together.
i. A _________________________is a substance made of the joined atoms of _____ or more
different _________________________
ii. Covalent bonds
1. Atoms ________________ electrons.
2. A ____________________ is a group of atoms held together by covalent bonds.
3. An example of a molecule is _______________
iii. Hydrogen Bonds
1. A Hydrogen bond is a ________________ chemical attraction between
______________ molecules.
2. Polar molecules have an ___________________ distribution of electrical charge (where
one end is positive and the other is negative like with water).
3. Non-polar molecules have an ______________distribution of electrical charge.
iv. Ionic Bonds
1. Atoms or molecules ___________ or _____________ electrons.
2. An ___________ is an atom that has gained or lost one or more electrons.
3. Ions of ________________ charge may interact to form an Ionic Bond
4. An example is _____________________________
II.
Water and Solutions – Nearly _______ % of your body is made of water.
a. Water stores heat efficiently
i. Water heats more ______________ and retains heat _________________ than many other
substances.
ii. Many organisms release excess heat through water ______________________.
iii. How do you release excess heat????
iv. Water helps cells maintain ________________________ because its ability to control
temperature enables cells to maintain constant internal temperature when the external
temperature changes drastically.
b. Water Bonds to itself and other substances.
i. ________________ is the attraction between substances of the same kind.
ii. Hydrogen bonds between water molecules cause the ________________ of liquid water.
iii. The attraction between water molecules causes a condition known as _____________
_____________________
iv. ______________ is an attraction between different substances.
v. Because of adhesion some substances get __________.
vi. The process in which water molecules move upward through a narrow tube (such as the stem of
a plant is called _________________ action.
1. Explain how capillary action works in a plant – summarize it.
c.
Water dissolves many substances – many substances dissolve in water A _______________ is a mixture
in which one or more substances are evenly distributed in another substance. Because some substances
dissolve easily in water, they can more easily move _____________ and ________________ cells.
i.
Polarity
1. The Polarity of water enables many substances to ____________________ in water.
2. _______________ compounds and ________________ molecules dissolve best in
water.
a. The ions or molecules become _________________ distributed in the water.
3. _______________ molecules do not dissolve well in water.
4. When nonpolar substances, such as oil, are placed in water, the water molecules are
______________ attracted to themselves than to the nonpolar molecules.
ii. Acids and bases
1.
The bonds of water are strong but may break forming a hydrogen ion _______ and a
hydroxide ion _________. (write the equation below)
2. Pure water always has a low concentration of ______________ ______ and
_____________________ _________.
3. ________ are coumpouds that form hydrogen ions when dissolved in water
a. When acids are added to water, they concentration of _______________ ions is
increased above that of pure water.
4. _______ are compounds that reduce the concentration of hydrogen ions when
dissolved in water. This happens because the hydroxide ions react with the hydrogen
ions to form _______________ molecules.
5. The ______ scale measures the concentration of _________________ ions in solutions.
6. The scale ranges from 0 - ___. Pure water has a pH value of ____.
7.
Acidic solutions pH value is ___________ 7. Basic solutions have pH values _________ 7 A solution with a
pH of 5 has ______ times as many hydrogen ions as a solution with a pH of 6.