Let's talk about changes....
How do we know what we know?
Atoms...are they indivisible?
Let's step into the 21 Century...
Moles...not the animal!
100
Kinetic theory says that as molecules heat up they move _?_. However, the more massive the particle, the _?_ it moves
faster; slower
100
Democritus wasn't a scientist, instead he was a _?_. Because of this he had no _?_ for his atomic theory, so it was rewritten
philosopher; evidence
100
What do the following terms represent in the structure of an atom? 1) atomic number; 2) atomic mass; 3) mass number 4) what 2 subatomic particles are always equal to each other in neutral atoms?
1) number of protons 2) weighted average of all the isotopes 3) protons + neutrons 4) protons + electrons
100
According to modern atomic theory, electrons behave like_?_ on a vibrating string. These electrons may be found only IN specific energy levels, not _?_ them.
waves; between
100
What is the mass of .20 mol of Nitrogen?
2.80 g
200
Name the phases of matter with the following characteristics: 1) holds its shape without a container 2) definite volume, but no definite shape 3) has the slowest moving molecules
1) solid; 2) liquid; 3) solid
200
Thomson discovered the negatively charged _?_ through an experiment called the _?_. He thought that these negatively charged subatomic particles were spread throughout an atom like _?_ in a cookie.
electrons, cathode-ray tube; raisins/chocolate chips
200
What is an atom's nucleus made of? What is found orbiting the nucleus? In modern atomic theory, these particles are found in _?_ which are regions of space inside energy levels.
protons and neutrons; electrons; orbitals
200
In modern atomic theory, the region of space where you are likely to find an electron is called a(n) _?_. The outermost electrons are called _?_ electrons and they determine the physical and chemical _?_ of an atom.
1) orbital; 2) valence; 3) properties.
200
What is the mass of .75 moles of sulfur?
24.08 g
300
Give the term that describes each of the following: 1) change of a substance from a solid directly to a gas 2) Change of a liquid to a gas 3) change of a liquid to a solid 4) change of a gas to a liquid
1) sublimation 2) evaporation 3) freezing 4) condensation
300
Rutherford discovered the positively charged _?_ through an experiment called the _?_.
nucleus (which contains protons); gold foil
300
Electrons, in the modern theory of the atom, can jump from energy level to energy level if they _?_. The number of electrons an atom has determines the number of _?_ required to hold all of those electrons. For example, a substance with 11 electrons would require _?_ energy levels.
gain or lose energy; energy levels; 3
300
Isotopes of a particular element differ from each other in their number of _?_. Because of this, isotopes have different _?_.
Neutrons; masses
300
How many moles are in 62.30 g of chromium?
1.20 Mole
400
When adding energy to a substance, the substance's temperature may increase or state may change, but not both. In which of the four terms is energy released? Which of the four terms is energy required? Four terms: Sublimation, freezing, condensation, evaporation
Energy is released: Freezing, Condensation Energy is required: Sublimation, Evaporation
400
Avogardro's number is useful for counting _?_. The number is _?_. It is defined as the number of particles in a _?_ of a substance.
atoms/molecules/particles; 6.02 x 10 ^23; mole
400
Three problems: 1) What is the mass of 2.5 mol of Ca? 2) If oxygen's number is 8 then it also has _?_. 3) Iron has an atomic mass of 56. Its atomic number is 26. How many neutrons does it have?
1) 100.25 g 2) 8 protons and 8 electrons 30 30 (56-26)
400
Calculate the molar mass of the following: 1) Ba 2) NH3
1) 137.30 g/mol 2) 17.03 g/mol
400
How many moles are in 176.20 g of magnesium?
7.25 moles
500
All matter is made of molecules or atoms that are constantly _?_. The faster they move, the _?_ the substance's temperature.
moving; higher
500
Name the units that coincide with the following: 1) Mass 2) Molar mass 3) Amount
1) g 2) g/mol 3) mol
500
Miscellaneous questions! 1) the unit that describes the amount of a substance is _?_ while the unit _?_ describes the mass of a substance. 2) An atom's mass number is equal to _?_ 3) You have 85.50 g F which has a molar mass of 19.0. How many moles of fluorine do you have? (Use dimensional analysis!!!!)
1) mole; grams 2) protons + neutrons 3) 4.5 moles
500
Convert the following into scientific notation: 1) 23,000 2) .000023
1) 2.30 x 10 ^4 2) 2.30 x 10 ^-5
500
This one is not about moles! 1) write the isotopic notation for Chlorine-37 2) How many of protons are in this atom? 3) How many neutrons are in this atom? 4) How many electrons are in this atom?
1) 37 over 17 next to Cl; 2) 17 3) 20 4) 17
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