MSU CEM 141 Questions with Detailed Verified
Answers
The statement "If I add cold milk to hot coffee the temperature will decrease," is a?
Ans: Claim, always include an explanation and reasoning to the claim.
Scientific Model Ans: Models are used to make testable predictions
How much is a picometer? Ans: 0.1 x 10^-12 meters
Atomic Force Microscopy/ Scanning Tunneling Microscopy Ans: Microscopes that
now allows us to view atoms.
Leaves are green in the summer because? Ans: 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? Ans: 91
What was Dalton's Atomic theory? (1808) Ans: - 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? Ans: 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? Ans: 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? Ans: A law describes - tells you
what happens
A theory explains - tells you why it happens
How big is an atom (H)? Ans: About 0.1 nanometer (0.1 x 10-9m)
Where did the idea of atoms come from? Ans: The Greeks
Atoms Ans: The smallest unit of an element
What is the evidence from Thomson's experiment that all atoms contain electrons?
Ans: The particles are identical regardless of the identity of the cathode(where they
were emitted from).
What is an alpha particle? Ans: Has 2 protons and 2 neutrons. It is the nucleus of a
Helium atom.
Coulomb's Law Ans: Negative and positive charges attract and like charges repel.
4 Types of Forces Ans: Gravitational, Electromagnetic, Strong Nuclear, Weak Nuclear
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, Gravitational Force Ans: Responsible for attraction between objects that have mass.
Electromagnetic Force Ans: Responsible for attraction/repulsion for objects that have
an electric charge.
Kinetic Energy Ans: The energy associated with motion.
Potential Energy Ans: The energy associated with the position of a system of objects
in a field.
How many molecules must be present for LDF's to exist? Ans: Two or more
As the helium atoms approach what happens to the total energy? Ans: Stays the same
As the helium atoms approach what happens to the kinetic energy? Ans: Increases
As the helium atoms approach what happens to the potential energy? Ans: Decreases
What happens to the total energy when the atoms get close to overlapping electron
clouds? Ans: Stays the same
What happens to the kinetic energy when the atoms get close to overlapping the
electron clouds? Ans: Decreases
What happens to the potential energy when the atoms overlap electron clouds? Ans:
Increases
Are gravitational forces meditated by fields? Ans: True
Do gravitational forces require 2 or more objects? Ans: True
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Answers
The statement "If I add cold milk to hot coffee the temperature will decrease," is a?
Ans: Claim, always include an explanation and reasoning to the claim.
Scientific Model Ans: Models are used to make testable predictions
How much is a picometer? Ans: 0.1 x 10^-12 meters
Atomic Force Microscopy/ Scanning Tunneling Microscopy Ans: Microscopes that
now allows us to view atoms.
Leaves are green in the summer because? Ans: 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? Ans: 91
What was Dalton's Atomic theory? (1808) Ans: - 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? Ans: 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? Ans: 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? Ans: A law describes - tells you
what happens
A theory explains - tells you why it happens
How big is an atom (H)? Ans: About 0.1 nanometer (0.1 x 10-9m)
Where did the idea of atoms come from? Ans: The Greeks
Atoms Ans: The smallest unit of an element
What is the evidence from Thomson's experiment that all atoms contain electrons?
Ans: The particles are identical regardless of the identity of the cathode(where they
were emitted from).
What is an alpha particle? Ans: Has 2 protons and 2 neutrons. It is the nucleus of a
Helium atom.
Coulomb's Law Ans: Negative and positive charges attract and like charges repel.
4 Types of Forces Ans: Gravitational, Electromagnetic, Strong Nuclear, Weak Nuclear
© Get it right 2025 Getaway - Stuvia US All rights reserved
, Gravitational Force Ans: Responsible for attraction between objects that have mass.
Electromagnetic Force Ans: Responsible for attraction/repulsion for objects that have
an electric charge.
Kinetic Energy Ans: The energy associated with motion.
Potential Energy Ans: The energy associated with the position of a system of objects
in a field.
How many molecules must be present for LDF's to exist? Ans: Two or more
As the helium atoms approach what happens to the total energy? Ans: Stays the same
As the helium atoms approach what happens to the kinetic energy? Ans: Increases
As the helium atoms approach what happens to the potential energy? Ans: Decreases
What happens to the total energy when the atoms get close to overlapping electron
clouds? Ans: Stays the same
What happens to the kinetic energy when the atoms get close to overlapping the
electron clouds? Ans: Decreases
What happens to the potential energy when the atoms overlap electron clouds? Ans:
Increases
Are gravitational forces meditated by fields? Ans: True
Do gravitational forces require 2 or more objects? Ans: True
© Get it right 2025 Getaway - Stuvia US All rights reserved
