CHEM FINAL- CH 1, 2, 3 & 4

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Chemistry is the study of...
Matter & the transformation of matter
Applied research:
Developing basic research; determining the lightest and strongest metal to be used for an airplane wing.
50mL small BBs + 50 mL large BBs = 90 mL of BBs
Many of the smaller BBs are able to fit within the pockets of space that were empty within the 50 mL of large BBs
Scientific hypothesis is:
Testable assumption used to explain an observation
Which of the following represents the largest quantity of mass?

a. 100 kg
b. 100,000,000,000 micrograms
c.100,000,000 milligrams
d. 100,000 g
e. All the masses are the same
All the masses are the same
Which has stronger attractions among its submicroscopic particles: a solid at 25 C or a gas at 25 C?
The attractions among the submicroscopic particles of the solid must be stronger than the attractions among the particles of the gas.
Which of the following statements best describes an element?
A material consisting of only one type of atom
Which of the following would be considered a physical property?
How many atoms of O are in H3OClO4?
5 atoms
If you filter sea water to remove all of the particles you would be left with a clear...
homogeneous mixture called a solution
Which of the following statements from Dalton's atomic theory would best describe the following observation:
Atoms can be neither created nor destroyed in a chemical reaction.
Which of the following statements best summarizes the Law of Definite Proportions?
The mass ratio of the elements in a compound will be the same regardless of how the compound was made.
The following statement describes which subatomic particle best? It has a relatively large mass
A proton and neutron (P&N)
If the particles of a cathode ray had a greater electric charge, the ray passing through a magnetic field would bend:
more because of a greater electromagnetic attraction
What does the following element description 186O?
an oxygen atom with 6 protons and 12 neutrons
If a material has a half-life of 24 hours, how long do you have to wait until the amount of radioisotope is 1/8 its original amount?
96 hours
A rem is:
A unit for measuring radiation exposure
Which of the following statements best describes the strong nuclear force?
The force is very strong but has a very short range. (Strong short little man)
Which of the following nuclear equations correctly describes alpha emission?
U ...Th + He (Uthhe)
Which of the following is a major disadvantage of nuclear-fission-based power plants?
The byproducts of the fission process are radioactive and have very long half-lives & The power plants are complex and there are many safety requirements to prevent contamination of the environment. (BYPRODUCTS RADIOACTIVE HALF-LIVES,COMPLEX SAFETY REQUIREMENTS)
When food is irradiated with gamma rays from a cobalt-60 source, does the food become radioactive? Why?
No. The gamma rays do not have sufficient energy to initiate the nuclear reaction in the atoms of the food.
An example of basic research is:
The study of the composition of the atom.
Not considered matter?
When water freezes it expands. What does this say about the density of ice compared with the density of water?
Ice is LESS DENSE than water because it has MORE VOLUME for the same mass.
The boiling point of methanol is 65 C and the boiling point of ethanol is 78 C. Which of the following statements is true?
At 70 C you would have methanol gas and liquid ethanol.
How many atoms are in one molecule of Na2SO4?
Which atom is largest?
Which of the following elements are in the same period as Mg?
Cl (Periods go across)
Elements that are in the same ______ have a tendency to have very similar chemical properties due to periodic trends.
Classify the following as element, compound, or mixture: table salt, stainless steel, table sugar, aluminum ice.
Compound; Mixture; Compound ; Element; Compound

Which of the following is NOT a property of an electron?
charge CHANGES depending on MASS
Which of the following statements from Dalton's atomic theory would best describe the following observation:

The mass of all of the products is equal to the mass of all the reactants in a given reaction.
Atoms can be neither created nor destroyed in a chemical reaction.
You heat 20 g of a metal in an open container and after the experiment you are left with 35 g of a powdery substance. Which statement best explains what happened?
The metal reacted with some air or something else we did not originally measure.
What does the following Element 238 92 U mean?
Uranium atom with 146 NEUTRONS and 92 PROTONS.
Why are the atomic masses listed in the periodic table not whole numbers?
The atomic masses are average atomic masses of various elemental isotopes
If an element has 18 protons and 20 neutrons and 18 electrons, which expression correctly identifies the element?
Argon-38 (18,20,18)
If a material has a half-life of 24 hours, how long do you have to wait until the amount of radioisotope is 1/4 its original amount?
48 hours
Why wouldn't you use carbon-14 dating on a piece of shell that was estimated to be 1 million years old?
The amount of radioactive carbon in the sample would probably be too small to measure.
What is the main technical difficulty in dealing with fusion reactions?
The amount of energy needed to overcome the electrical repulsion of the reactants is extremely high
How is it possible for an element ot decay "forward in the periodic table"-- that is, to decay to an element of higher atomic number?
As a beta particle is released, a neutron transforms into a proton (DECAY HIGHER=TRANSFORMER PROTON)