BY 30 – Fall 2001
2.1.
Atoms:
a. The scientific discipline of chemistry is subdivided into __________________ chemistry and ____________________ chemistry, the difference being that __________________ chemistry deals with compounds that contain carbon.
b. All matter consists of different _______________________ of which there are 112 different ones. Of these the symbol for calcium is ______________; sodium is _______________; potassium is ___________________; carbon is ___________________; hydrogen is ____________________; nitrogen is _______________________; and oxygen is ________________________.
c. Each element is composed of individual _________________________, the smallest unit that still retains the properties and characteristics of that element.
d. The nucleus of an atom contains two types of particles called ______________________ and ____________________. Of these two, only ___________________ are charged and carry a net ____________________ charge.
e. Surrounding the nucleus of an atom is the _____________________________ containing ______________________ that carry a net ___________________ charge.
f. The inner shell of the electron cloud of an atom can hold a maximum of ___________________ electrons while the second shell can hold a maximum of ______________________ electrons.
g. The number of _________________________ within the nucleus of an atom determines the atomic number for that element. By contrast the sum of protons and neutrons determines the ________________________ of that element.
h. When different atoms of the same element have different numbers of neutrons, these different atoms are called _________________________. Of the various types, the ones whose nuclei decay into more stable structures, releasing radioactivity are called _____________________.
i. The atomic mass (or weight) of an element does not always equal the atomic mass number, the reason being that there are more than one _____________________________ for that element. The atomic mass (or weight) of an element is given in units of __________________________.
2.2.
Ions, Molecules, and Compounds
a. When an atom loses or gains an electron it becomes an __________________. In this case, those carrying positive charges are called ___________________ while those carrying negative charges are called _______________________.
b. When two adjacent atoms are joined together, the result is called a ________________________. When the atoms are from different elements the term _______________________ can be used.
c. Molecules and compounds are the products of ________________________ which hold atoms together through the interactions of electrons in their outer shells.
2.3.
Chemical Bonds
a. Chemical bonds come in three basic types called _______________________, ________________________, and ____________________________ bonds.
b. ___________________________ bonds form as a result of an electron being transferred from one atom to an atom of a different element, the result being that both atoms become ions.
c. An example of a compound held together by ionic bonds is NaCl. In this case, the transfer of an electron from __________________________ to ______________________ results in full electron shells for both sodium and chlorine. NaCl exists as a _______________________ composed of a crystal matrix that consists of repeating ________________________ and ___________________________________.
d. When an ionic compound is placed into water, it dissociates into individual ions called ______________________________________.
e. ________________________ bonds form when two atoms share one or more pairs of electrons. When the sharing involves a single pair of electrons this is called a ___________________ bond; when the sharing involves two pairs, this is called a ____________________; and when the sharing involves three pairs, this is called a _____________________ bond.
f. A carbon dioxide molecule (CO2) is formed as a result of carbon forming ___________________________ bonds with each of the two oxygen atoms.
g. ______________________ covalent bonds refer to covalent bonds in which one atom does not attract the shared electrons more strongly than the other. By contrast in _________________________ covalent bonds the sharing is unequal.
h. As a result of polar covalent bonds in a water (H2O) molecule, the oxygen-end of the molecule has a partial ______________________ charge while the two hydrogen ends have partial ______________________ charges.
i. The type of interaction which results from the attraction between the partial positive charge of a hydrogen atom and the partial negative charge of either oxygen or nitrogen is called a ____________________________ bond.
j. Hydrogen bonds typically link two __________________________ or hold different parts of a molecule together in a particular _____________________________________.
2.4.
Chemical Reactions
a. Chemical reactions occur whenever new ____________________________ are formed or old bonds are ___________________________.
b. Chemical reactions are typically written in the form of a _______________________________ in which the _____________________ appear on the left and ______________________ on the right.
c. In a balanced chemical reaction, the law of conservation of mass states that the total mass of ___________________________ must equal the total mass of ________________________.
d. Chemical reactions that release more energy than they absorb are called _____________________________ while ___________________________ reactions are those that absorb more energy than they release.
e. The ____________________________ energy refers to the collision energy needed to produce the formation or destruction of chemical bonds.
f. The factors that influence the rate of chemical reactions include _____________________________, ________________________________, ___________________________, and _______________________________.
g. The factors that speed up reactions include an _____________________ in temperature; a ___________________________ in the size of particles; an _______________________________ in concentrations, and the lowering of the __________________________ by catalysts.
h. The formation of proteins from combining individual amino acids represents an example of a _______________________________ reaction whereas the breakdown of starch into individual glucose molecules is an example of a __________________________________ reaction.
i. Another name for a synthesis reaction is _____________________________ and is usually __________________________. Another name for a decomposition reaction is ___________________________ and is usually __________________________________.
j. A reaction in which a molecule loses electrons is called ______________________ whereas the term __________________________ is used when a molecule gains electrons. For example, lactic acid is ___________________________ to form pyruvic acid whereas pyruvic acid is _________________________ to form lactic acid.
2.5.
Types of Mixtures
a. A ________________________________ is a combination of two or more components that are physically intermixed but not bound by chemical bonds.
b. The three basic types of mixtures are ______________________________, _________________________, and _______________________________.
c. In the most common type of solution in the body, water represents the ____________________________ while dissolved molecules represent the ____________________________.
d. The concentration of solutions can be expressed as a weight/volume ratio or in terms of its ________________________, in units of ___________________.
e. A mole of a substance is equal to its atomic or molecular weight weighed out in _____________________ and represents a number of these particles equal to _________________________, also known as ______________________ number.
f. A _____________________________ refers to a solution in which the solute particles are large enough to render the solution cloudy or opaque.
g. A ___________________________ refers to a solution in which the solutes eventually settle out of solution.
2.6.
Water
a. Water is the most important molecule in the body because of a number of properties which include its ____________________________________, _____________________________, ______________________________, ___________________________, and _____________________________.
b. Water is known as the universal solvent primarily because of its ______________________________ covalent bonds. Solutes which contain polar bonds are called ____________________________ and dissolve easily, whereas solutes which contain _______________________ bonds are called hydrophobic and do not dissolve easily.
c. For hydrophilic substances, water molecules cluster around the molecule forming a _____________________________.
d. The property of reactivity refers to the fact that water serves as a ______________________________ in hydrolysis reactions and as a ______________________________ in dehydration-synthesis reactions.
e. Water has a __________________________ heat capacity meaning that it can absorb a relatively large amount of ________________________ with only a modest temperature increase. This property results from the fact that as water absorbs heat, some of this energy is used to break ______________________ leaving less energy to increase temperature.
f. Water has a _________________________ heat of vaporization meaning that it takes a large amount of heat to _____________________ water. As a result of this property, a large amount of ______________________ is removed from the body surface as sweat evaporates.
g. Water forms a _______________________ around certain body organs protecting them.
2.7.
Acids and Bases
a. Like salts, acids and bases dissociate into ______________________ when placed in water.
b. An acid is any substance that releases ___________________ into solution upon dissociation. By contrast, a base releases _______________________. Thus acids are known as __________________ donors while bases are known as proton ________________________.
c. When acids and bases are mixed together, they react with a displacement reaction to form a salt and ____________________________.
d. The higher the __________________________, the more acidic a solution is. The relative concentration of H+ is expressed by the ___________________ scale which varies from ____________________ to ___________________.
e. At
a pH of 7, also called ______________________ pH, the concentration of H+
is equal to ________________________ and the concentration of
f. The pH of blood only varies between __________________________ as a result of ______________________________. A buffer releases ________________________ when the pH rises and __________________ when the pH falls.
g. A ___________________ acid is one that dissociates completely and irreversibly whereas a ____________________acid is one that only partially dissociates and is ___________________________.
h. The dissociation of H2CO3 into H+ and HCO3- proceeds to the right when pH ___________________ and to the left when pH ____________________.