CEM 141 MSU Exam 1 ACTUAL
QUESTIONS AND CORRECT ANSWERS
The statement "If I add cold milk to hot coffee the temperature will decrease," is a? - CORRECT
ANSWER Claim, always include an explanation and reasoning to the claim.
Scientific Model - CORRECT ANSWER Models are used to make testable predictions
How much is a picometer? - CORRECT ANSWER 0.1 x 10^-12 meters
Atomic Force Microscopy/ Scanning Tunneling Microscopy - CORRECT ANSWER
Microscopes that now allows us to view atoms.
Leaves are green in the summer because? - CORRECT ANSWER A plant's leaves are green in
the summer because they contain chlorophyll. Chlorophyll is a natural pigment that absorbs all
wavelengths in the visible spectrum except green.
How many naturally occurring elements exist? - CORRECT ANSWER 91
What was Dalton's Atomic theory? (1808) - CORRECT ANSWER - Elements are composed of
small particles called Atoms.
- Atoms of a given element are different from atoms of other elements.
-Chemical reactions happen when atoms are rearranged.
- Compounds contain 2 or more elements.
What was J.J. Thomson's experiment, and what did he discover? - CORRECT ANSWER Using
a Cathode Ray Tube, he noticed that particles emerged to the cathode disk, and moved to another, the
anode. These particles could be deflected by electrical fields that would indicate that they would be
negatively charged. They were also deflected by magnetic fields, which showed the particles carried
the charge as the ray was bent. The most important observation was that the type of cathode used did
not matter, as these particles were still emitted. Therefore, Thomson deduced that the particles were
universal and were in fact negatively charged components of the atom. (The Electron)
, What was Ernest Rutherford's experiment, what did he discover? - CORRECT ANSWER
Ernest Rutherford fired Alpha particles (Hydrogen atoms) at a thin sheet of gold foil. Had
Thomson's theory been right about the plum pudding model, then the atoms should have all passed
right through the sheet with no exceptions. However, a small ratio of these particles were deflected.
With this information, Rutherford figured there was a small dense nucleus in the atom and that most
of the atom was empty space.
What is the difference between Law and Theory? - CORRECT ANSWER A law describes -
tells you what happens
A theory explains - tells you why it happens
How big is an atom (H)? - CORRECT ANSWER About 0.1 nanometer (0.1 x 10-9m)
Which is biggest? Atom, Molecule, Cell, or it depends? - CORRECT ANSWER
Where did the idea of atoms come from? - CORRECT ANSWER The Greeks
Atoms - CORRECT ANSWER The smallest unit of an element
What is the evidence from Thomson's experiment that all atoms contain electrons? - CORRECT
ANSWER The particles are identical regardless of the identity of the cathode(where they were
emitted from).
What is an alpha particle? - CORRECT ANSWER Has 2 protons and 2 neutrons. It is the
nucleus of a Helium atom.
Coulomb's Law - CORRECT ANSWER Negative and positive charges attract and like charges
repel.
4 Types of Forces - CORRECT ANSWER Gravitational, Electromagnetic, Strong Nuclear,
Weak Nuclear
Gravitational Force - CORRECT ANSWER Responsible for attraction between objects that
have mass.
QUESTIONS AND CORRECT ANSWERS
The statement "If I add cold milk to hot coffee the temperature will decrease," is a? - CORRECT
ANSWER Claim, always include an explanation and reasoning to the claim.
Scientific Model - CORRECT ANSWER Models are used to make testable predictions
How much is a picometer? - CORRECT ANSWER 0.1 x 10^-12 meters
Atomic Force Microscopy/ Scanning Tunneling Microscopy - CORRECT ANSWER
Microscopes that now allows us to view atoms.
Leaves are green in the summer because? - CORRECT ANSWER A plant's leaves are green in
the summer because they contain chlorophyll. Chlorophyll is a natural pigment that absorbs all
wavelengths in the visible spectrum except green.
How many naturally occurring elements exist? - CORRECT ANSWER 91
What was Dalton's Atomic theory? (1808) - CORRECT ANSWER - Elements are composed of
small particles called Atoms.
- Atoms of a given element are different from atoms of other elements.
-Chemical reactions happen when atoms are rearranged.
- Compounds contain 2 or more elements.
What was J.J. Thomson's experiment, and what did he discover? - CORRECT ANSWER Using
a Cathode Ray Tube, he noticed that particles emerged to the cathode disk, and moved to another, the
anode. These particles could be deflected by electrical fields that would indicate that they would be
negatively charged. They were also deflected by magnetic fields, which showed the particles carried
the charge as the ray was bent. The most important observation was that the type of cathode used did
not matter, as these particles were still emitted. Therefore, Thomson deduced that the particles were
universal and were in fact negatively charged components of the atom. (The Electron)
, What was Ernest Rutherford's experiment, what did he discover? - CORRECT ANSWER
Ernest Rutherford fired Alpha particles (Hydrogen atoms) at a thin sheet of gold foil. Had
Thomson's theory been right about the plum pudding model, then the atoms should have all passed
right through the sheet with no exceptions. However, a small ratio of these particles were deflected.
With this information, Rutherford figured there was a small dense nucleus in the atom and that most
of the atom was empty space.
What is the difference between Law and Theory? - CORRECT ANSWER A law describes -
tells you what happens
A theory explains - tells you why it happens
How big is an atom (H)? - CORRECT ANSWER About 0.1 nanometer (0.1 x 10-9m)
Which is biggest? Atom, Molecule, Cell, or it depends? - CORRECT ANSWER
Where did the idea of atoms come from? - CORRECT ANSWER The Greeks
Atoms - CORRECT ANSWER The smallest unit of an element
What is the evidence from Thomson's experiment that all atoms contain electrons? - CORRECT
ANSWER The particles are identical regardless of the identity of the cathode(where they were
emitted from).
What is an alpha particle? - CORRECT ANSWER Has 2 protons and 2 neutrons. It is the
nucleus of a Helium atom.
Coulomb's Law - CORRECT ANSWER Negative and positive charges attract and like charges
repel.
4 Types of Forces - CORRECT ANSWER Gravitational, Electromagnetic, Strong Nuclear,
Weak Nuclear
Gravitational Force - CORRECT ANSWER Responsible for attraction between objects that
have mass.
