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Assignment #2 - Chemistry Review
Name _______________________________ Date ________ Period ________
Make sure to cite your sources used on bottom of the last page of this
Chemistry review in APA format.
KEY TERMS:
Matter physical substance in general, as distinct from mind and spirit; (in physics)
that which occupies space and possesses rest mass, especially as distinct
from energy.
Inorganic not consisting of or deriving from living matter.
Atom the basic unit of a chemical element.
Element a part or aspect of something abstract, especially
one that is essential or characteristic.
Atomic nucleus central part of the atom.
Proton a stable subatomic particle occurring in all atomic nuclei, with a
positive electric charge equal in magnitude to that of an electron, but
of opposite sign.
Neutron a subatomic particle of about the same mass as a proton
but without an electric charge, present in all atomic
nuclei except those of ordinary hydrogen.
number of protons in the nucleus of an atom, which determines the
Atomic number the
chemical properties of an element and its place in the periodic table.
Mass number (=atomic weight) the total number of protons and neutrons in a
nucleus.
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of two or more forms of the same element that contain equal numbers
Isotope each
of protons but different numbers of neutrons in their nuclei, and hence differ
in relative atomic mass but not in chemical properties; in particular, a
radioactive form of an element.
Electron a stable subatomic particle with a charge of negative electricity, found in all atoms
and acting as the primary carrier of electricity in solids.
Valence electrons an electron of an atom, located in the outermost shell (valence
shell) of the atom
Orbital each of the actual or potential patterns of electron density that may be formed in an
atom or molecule by one or more electrons, and that can be represented as a wave
function. relating to an orbit or orbits.
Octet rule principle that bonded atoms prefer to have 8 electrons in valence shells.
Half-life the time taken for the radioactivity of a specified isotope to fall to half its original
value.
Radioactive tracer radioactive element or compound added to material to monitor the
material's distribution as it progresses through a system.
Ion an atom or molecule with a net electric charge due to
the loss or gain of one or more electrons.
the disconnection or separation of something from something else or the state
Dissociation of being disconnected.
Ionic bond is the complete transfer of valence electron(s) between atoms.
Valence the combining power of an element, especially as measured by the
number of hydrogen atoms it can displace or combine with.
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Ionization
the complete loss of an electron from an atomic or
molecular species.
Molecule a group of atoms bonded together, representing the smallest fundamental unit of a
chemical compound that can take part in a chemical reaction.
Molecular formula a formula giving the number of atoms of each of the elements present in
one molecule of a specific compound.
Structural formula a formula which shows the arrangement of atoms in the molecule of a
compound.
Compound a thing that is composed of two or more separate elements; a mixture.
Acid a molecule or other entity that can donate a proton or accept an electron pair in reactions.
lowest part or edge of something, especially the part on which it rests or is
Base the
supported.
Hydrogen ion strictly, the nucleus of a hydrogen atom separated from its accompanying
electron.
Hydroxide ion negatively charged molecule made up of one oxygen bonded to one
hydrogen.
PH measure of hydrogen ion concentration, a measure of the acidity or alkalinity of a
solution.
Buffer a solution that resists changes in pH when acid or alkali is added to it. Buffers typically
involve a weak acid or alkali together with one of its salts.
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Nonpolar covalent bond type of chemical bond that exists between two atoms.
Polar covalent bond chemical bond in which the electrons required to form a bond is
unequally shared between two atoms
Ionic bond complete transfer of valence electron(s) between atoms.
Anion ionic species having a negative charge.
Cation positively charged particles that form when an atom or compound loses one or more
electrons.
Hydrogen bond a weak bond between two molecules resulting from an electrostatic
attraction between a proton in one molecule and an electronegative
atom in the other.
Hydrophobic fail to mix with water
Hydrophobic interactions the interactions between water and hydrophobes
Hydration the process of causing something to absorb water
Hydrophilic tendency to mix with water
Bound water an extremely thin layer of water surrounding a mineral
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the tension of the surface film of a liquid
caused by the attraction of the particles in the
Surface tension surface layer by the bulk of
the liquid, which tends to minimize surface
area.
Capillarity (=capillary action)
the tendency of a liquid in a capillary tube or absorbent material to rise or fall as a result of surface
tension.
Specific heat
the heat required to raise the temperature of the unit mass of a given substance by a
given amount (usually one degree).
Freezing point of water
Heat of vaporization
Solvent
Solute
32 degrees Fahrenheit or 0 degrees Celsius
100 degrees Celsius
the liquid in which a solute is dissolved to form a solution.
the minor component in a solution, dissolved in the solvent.
Aqueous solution
solution where solvent is water
QUESTIONS
1. Describe atomic structure using the terms proton,
neutron, electron, mass number and orbital. Indicate
what is meant by electrons in an "excited state" and those
in a "ground state"
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2. Explain what an isotope is and give two important
physical properties of isotopes that make them useful in
biological research. Define half-life.
Isotopes are groups of atoms that share the same chemical properties but have different masses. They are
useful in dating artifacts, and medical diagnosis. Half life is the time taken for the radioactivity of a specified
isotope to fall to half its original value.
3. Using diagrams, explain what an ion is, and how it
forms. Describe an ionic bond.
4. Explain what is meant by pH. Give the name of
materials that resist a change in pH.
In chemistry, pH is a scale used to specify how acidic or basic a water-based solution is. A buffer resists a
change in pH.
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5. Describe a covalent bond and tell how it differs from an
ionic bond. Relate the structure of an atom to its chemical
properties and to the type of chemical bond it forms.
6. Explain the important role of weak chemical bonds in
the organization of living things.Weak bonds may be easily broken but they are very
important because they help to determine and
stabilize the shapes of biological molecules.
7. Describe the special physical properties of water. Draw
two water molecules in a way that illustrates a hydrogen
bond, explain why water is a good solvent, and show the
basis for the high surface tension of water.
Boiling points, surface tension, gas state. OHO . Water is capable of dissolving a variety of
different substances, which is why it is such a good solvent.
How do the unique chemical and physical properties of
water make life on earth possible?
A high surface tension exists with water. Due to cohesion, water molecules have
hydrogen bonds which attract to one another. This is important in transpiration, as
the water molecules stick to each other as they move up a tree.
8. Indicate why oxygen and carbon dioxide are basic to
life, and name the principle source of each of these
molecules.
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9. How do mixtures, compounds, and molecules differ from
each other?
Compound: two or more different atoms chemically bonded together. Molecule: two
or more different or same atoms chemically bonded together. A mixture contains two
or more substances (elements, lattices, molecules, compounds), that are not
chemically bonded together.
10. What is the difference between a polar and nonpolar
covalent bond?
Nonpolar covalent bonds are a type of chemical bond where two atoms share a pair
of electrons with each other. Polar covalent bonding is a type of chemical bond
where a pair of electrons is unequally shared between two atoms.
11. What properties of water make it an essential
component of living material?
Water is polar so they form hydrogen bonds giving them unique properties
such as a relatively high boiling point, high specific heat, cohesion,
adhesion and density.
12. Why are buffers important to living things? Explain
how a buffer system works.
They are important to maintain homeostasis by maintaining a more constant pH
13. Explain why isotopes are important in biochemical
research?
An isotope is important because they behave similarly chemically but different in physical characteristics
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