Properties of Elements
And the Periodic Table
Ionic/Covalent Bonds
Mass/Density/Etc
Nuclear Chemistry
Random (But Important)
100
Which type of property cannot be observed without changing the composition of a substance?
A Chemical Change
100
What are valence electrons?
Electrons in the highest occupied energy level.
100
What is the conversion factor for the volume of a gas?
moles of gas(22.4 L/1 mol)
100
What is the difference between an isotope and a radioisotope?
Each isotope of an element has the same atomic number, but a different atomic mass. A radioisotope is an isotope that is radioactive.
100
Define a Lewis Acid and a Lewis Base.
Acid-A substance that can accept a pair of electrons to form a covalent bond. Base-A substance that can donate a pair of electrons to form a covalent bond.
200
Assume that water, mercury, and gallium are all at 40 degrees c. As the temperature drops, which substance will freeze first?
Gallium
200
Why are Ionic Compounds electrically neutral?
The positive charges balance the negative charges.
200
What is the definition of percent composition?
Percent by mass of each element in a compound. (Mass of Element/Mass of Compound) *100%= %mass of element
200
What happens to an atom with a nucleus that falls outside the band of stability?
It begins to undergo nuclear decay.
200
What is entropy?
Measure of the disorder of a system.
300
How does the ionic radius of a typical anion compare with the radius of the corresponding neutral atom?
The anion is larger.
300
Write the electron dot structures for each of the following elements: -C -Be -O
See answer sheet for drawings.
300
What is Avagadro's Hypothesis?
Equal volume of gasses at the same temperature and pressure contain equal numbers of particles.
300
Define artificial radioactivity and natural radioactivity.
Artificial radioactivity comes from elements created in nuclear reactors and accelerators. Natural radioactivity comes from elements in nature.
300
What are alloys?
Mixtures composed of 2 or more elements at least one of which being a metal.
400
In a neutral atom, the number of which two subatomic particles must always be equal?
Protons and Neutrons
400
Which of the following molecules contains a central atom that does not obey the octet rule? a)PBr-5 b)AlI-3 c)PF-3
A)Phosphorus-(Has 10 Valence electrons)
400
A solution has a volume of 250 mL and contains 0.70 mol NaCl. What is its molarity?
2.8M
400
Radioactive Isotopes used internally for diagnosis have relatively short half-lives. Why is this important?
Patients are exposed to radiation for shorter amounts of time.
400
How do you determine the polarity of a molecule?
1) Determine which bonds are polar/non-polar. 2) Use shape to determine overall polarity of molecule (symmetry, etc)
500
Which of these statements about the periodic table is correct? 1) Elements are arranged in order of increasing atomic mass. 2) A period is a horizontal row. 3) Nonmetals are located on the right side of the table. A- 1 only B-1 and 2 C-All of them D-2 and 3
D-2 and 3 only
500
Write the electron configuration for each ion. a)Oxide Ion b)Magnesium Ion c)Nitride Ion d)Potassium Ion
See Answer sheet for configurations.
500
How many grams of sodium flouride are needed to prepare a 0.400m NaF solution that contains 750 g. water?
1.26*10^1 g. NaF
500
How are the mass number and atomic number of a nucleus affected by the loss of the following? a)Beta particle b)Alpha particle c)Gamma Ray
a-mass number unchanged, atomic number increase by 1 b-mass number decrease by 4, atomic number decrease by 2 c-mass number and atomic number remain unchanged
500
Without looking at the poster on the west wall or your yellow sheet. Name the 7 Steps of the Scientific method in order.
1) Choose a problem. 2) Research your problem. 3) Develop a Hypothesis. 4) Design an experiment. 5) Test your Hypothesis. 6) Organize your data. 7) Draw Conclusions.
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