CEM 141 MSU Exam 1
QUESTIONS WITH ANSWERS 2025/2026
The statement "If I add cold milk to hot coffee the temperature will
decrease," is a? - ✔✔Claim, always include an explanation and
reasoning to the claim.
Scientific Model - ✔✔Models are used to make testable predictions
How much is a picometer? - ✔✔0.1 x 10^-12 meters
Atomic Force Microscopy/ Scanning Tunneling Microscopy -
✔✔Microscopes that now allows us to view atoms.
Leaves are green in the summer because? - ✔✔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? - ✔✔91
,What was Dalton's Atomic theory? (1808) - ✔✔- 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? -
✔✔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? -
✔✔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? - ✔✔A law describes -
tells you what happens
A theory explains - tells you why it happens
How big is an atom (H)? - ✔✔About 0.1 nanometer (0.1 x 10-9m)
Which is biggest? Atom, Molecule, Cell, or it depends? - ✔✔
Where did the idea of atoms come from? - ✔✔The Greeks
Atoms - ✔✔The smallest unit of an element
What is the evidence from Thomson's experiment that all atoms
contain electrons? - ✔✔The particles are identical regardless of the
identity of the cathode(where they were emitted from).
What is an alpha particle? - ✔✔Has 2 protons and 2 neutrons. It is the
nucleus of a Helium atom.
Coulomb's Law - ✔✔Negative and positive charges attract and like
charges repel.
QUESTIONS WITH ANSWERS 2025/2026
The statement "If I add cold milk to hot coffee the temperature will
decrease," is a? - ✔✔Claim, always include an explanation and
reasoning to the claim.
Scientific Model - ✔✔Models are used to make testable predictions
How much is a picometer? - ✔✔0.1 x 10^-12 meters
Atomic Force Microscopy/ Scanning Tunneling Microscopy -
✔✔Microscopes that now allows us to view atoms.
Leaves are green in the summer because? - ✔✔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? - ✔✔91
,What was Dalton's Atomic theory? (1808) - ✔✔- 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? -
✔✔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? -
✔✔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? - ✔✔A law describes -
tells you what happens
A theory explains - tells you why it happens
How big is an atom (H)? - ✔✔About 0.1 nanometer (0.1 x 10-9m)
Which is biggest? Atom, Molecule, Cell, or it depends? - ✔✔
Where did the idea of atoms come from? - ✔✔The Greeks
Atoms - ✔✔The smallest unit of an element
What is the evidence from Thomson's experiment that all atoms
contain electrons? - ✔✔The particles are identical regardless of the
identity of the cathode(where they were emitted from).
What is an alpha particle? - ✔✔Has 2 protons and 2 neutrons. It is the
nucleus of a Helium atom.
Coulomb's Law - ✔✔Negative and positive charges attract and like
charges repel.
