Chemistry Final (Prentice-Hall)
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- What is chemistry?
- The study of the composition and change of matter.
- Name the 5 major areas of Chemistry.
- Organic (any substance with carbon), Inorganic, Analytical (what substances are made up of), Physical (behavior of substances), Biochemistry (chemistry applied to life).
- Name the 6 areas of impact in chemistry
- Materials, Energy, Medical, Farming, Environment, Space
- What is the scientific method?
- Observations, hypothesis, experiment, theory
- What is matter?
- Anything that has mass and takes up space
- What are the three states of matter?
- Solid, liquid, gas
- Explain chemical vs. physical change
- Chemical change is something that alters the chemical make-up of the compound. Physical change is something that alters a material without changing its chemical make-up.
- What is a scientific law? A theory?
- A scientific law is a consise statement that summarizes the results of many observations and experiments. A theory explains WHY this law is.
- What is the difference between a heterogeneous and a homogeneous mixture?
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Heterogeneous mixture: Not uniform in composition
Homogeneous: Completely uniform in composition - Matter that has a uniform and definite composition is called a ________.
- Substance
- What is distillation?
- When a liquid is boiled to produce a vapor that is then condensed again to a liquid.
- What is a compound?
- A substance that can be separated into simpler substances only by chemical means.
- What is the law of conservation of mass?
- Mass is never, ever created nor destroyed, no matter what.
- What is the difference between a qualitative and a quantitative measurement?
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Qualitative: Gives results in a non-numerical form.
Quantitative: Gives definite answers in a numerical or unit form. -
What is wrong with this equation?
.8 x 10^4 What is the correct answer? - In scientific notation, the coefficient is always a number between 0 and 9. 8 x 10^3
- What is the difference between accuracy and precision?
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Accuracy: Measure of how close a measurement is to an actual measurement.
Precision: Measure of how close a series of measurements are to one another. - How do you find a percent error?
- The absolute value of the error divided by the accepted value x 100%.
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How many significant digits are in
a.) 2.803
b.) 2.083
c.) 0.083 -
a.) 4
b.) 4
c.) 2 - What is the International System of Units?
- A revised version of the metric system.
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What are the basic units of the following properties of matter?
a.) Size
b.) Volume
c.) Mass -
a.) Meter
c.) Liter
d.) Kilogram - How do you determine density?
- Mass divided by volume.
- What does temperature measure?
- The amount of heat transfer
- What are the three steps to solving a chemistry problem?
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Analyze
Calculate
Evaluate - What is dimensional analysis?
- A way to analyze and solve problems using the dimensions (units) of the measurements.
- What is Dalton's atomic theory?
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1. All elements are composed of tiny indivisible particles called atoms.
2. Atoms of the same element are identical. The atoms of any one element are different from those of any other element. -
Where are these found in an atom?
a.) Nucleus
b.) Electrons
c.) Protons
d.) Neutrons -
a.) In the center of the atom
b.) Around the center, in rings
c.) In the center (the nucleus)
d.) Also in the center (the nucleus) - How many atoms are in a mole?
- 6.02 x 10^23
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What are the charges of the following?
a.) Protons
b.) Neutrons
c.) Electrons -
a.) Positive
b.) Neutral
c.) Negative - How were electrons discovered?
- By a cathode ray (a beam that travelled from the cathode to the anode in an experiment involving a glass tubes with electrodes on each end)
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Who discovered each of the following and when:
a.) Protons
b.) Neutrons
c.) Electrons -
a.) E. Goldstein, 1886
b.) James Chadwick, 1832
c.) J.J. Thomson, 1897 - In Rutherford's experiment involving the piece of gold foil and a beam of alpha particles, some alpha particles bounced off the foil while most when straight through the foil. What was Rutherford's reasoning for this?
- That the atom is mostly empty space.
- What does the atomic number of an element tell you?
- The number of protons that are in an atom of that element.
- What does the mass number mean?
- Total number of protons and neutrons in an atom.
- What is an isotope?
- Atoms that have the same number of protons but different numbers of neutrons.
- Is an atom positively, negatively, or neutrally charged? Why?
- Because the protons (positive charge) and the electrons (negative charge) cancel out each other's charge.
- What is the atomic mass?
- The weighted average of teh atoms in a naturally occurring sample of the element.
- Who was the first person to list the elements in a systematic way?
- Dmitri Mendeleev
- Who arranged the elements in the way that our periodic table is still written?
- Henry Moseley
- What are the horizontal rows of the periodic table called? What is significant about elements in the same horizontal row?
- Horizontal rows are called periods. Elements in the same period have similar characteristics.
- What is the periodic law?
- When the elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.
- What are radioisotopes?
- Unstable isotopes
- What is radioactivity?
- When materials give off rays because of changes in the nuclei
- What is radiation?
- The penetrating rays and particles emitted by a radioactive source
- What 3 scientists discovered radioactivity?
- Antoine Henri Becquerel, Marie Curie, and Pierre Curie (bet you can't guess who was husband and wife)
- What is radioactive decay?
- When an unstable nucelus loses energy by emitting radiation
- What are the 3 types of radiation?
- Alpha, beta, and gamma