CHEM 121 EXAM 1- CHAPTERS 1 AND
2 QUESTIONS & ACCURATE
ANSWERS PASSED 100%
Atoms - Correct Answer ✔✔ submicroscopic particles that constitute the fundamental
building blocks of ordinary matter.
Molecules - Correct Answer ✔✔ Atoms combine to form these
Allotropes - Correct Answer ✔✔ Forms of an element (the same element) with different
atomic/molecular structure
What is the approach to scientific knowledge? - Correct Answer ✔✔ Observation and
experiment
Scientific method - Correct Answer ✔✔ process for understanding nature by observing
nature and its behavior, and by conducting experiments to test our ideas.
What are the key characteristics of the scientific method? - Correct Answer ✔✔ -
Observation
- Formulation of hypotheses
- Experimentation
- Formulation of laws and theories
Observations (Data) - Correct Answer ✔✔ Descriptions about the characteristics or
behavior of nature
Hypothesis - Correct Answer ✔✔ Tentative interpretation or explanation of the
observations.
A good hypothesis is falsifiable.
- The results of an experiment may support a hypothesis or prove it wrong, in which
case the scientist must modify or discard the hypothesis.
Scientific Law - Correct Answer ✔✔ A brief statement that summarizes past
observations and predicts future ones
Law of Conservation of Mass - Correct Answer ✔✔ "In a chemical reaction, matter is
neither created nor destroyed"
, Scientific Theory - Correct Answer ✔✔ Model for the way nature is and tries to explain
not merely what nature does, but why. They are validated by experiments but can never
be proven conclusively because a flaw could be found.
Matter - Correct Answer ✔✔ Anything that occupies space and has mass and is
classified by its state (its physical form) and its composition (basic components that
make it up)
Can be classified as:
- solid
- liquid
- gas
Solid matter - Correct Answer ✔✔ Atoms or molecules pack close to each other in fixed
locations. They have fixed volume and rigid shape.
Crystallin - Correct Answer ✔✔
Amorphous - Correct Answer ✔✔ atoms or molecules do not have any long-range order
(i.e., glass and plastic)
Liquid matter - Correct Answer ✔✔ atoms or molecules pack about as closely as they
do in solid matter, they are are free to move relative to each other. Have fixed volume
but not fixed shape.
Gaseous matter - Correct Answer ✔✔ atoms or molecules have a lot of space between
them, are free to move relative to one another, and are compressible.
Pure substance - Correct Answer ✔✔ made up of only one component and its
composition is invariant. Either element or compound.
Element - Correct Answer ✔✔ substance that cannot be chemically broken down into
simpler substances
Compound - Correct Answer ✔✔ substance composed of two or more elements in fixed
definite proportions
Mixture - Correct Answer ✔✔ substance composed of two or more compound in
proportions that can vary from one sample to another. These are either heterogeneous
or homogeneous.
Heterogeneous mixture - Correct Answer ✔✔ the composition varies from one region of
the mixture to another (i.e., salt and sand)
Homogeneous mixture - Correct Answer ✔✔ made of multiple substances but appears
to be one substance
2 QUESTIONS & ACCURATE
ANSWERS PASSED 100%
Atoms - Correct Answer ✔✔ submicroscopic particles that constitute the fundamental
building blocks of ordinary matter.
Molecules - Correct Answer ✔✔ Atoms combine to form these
Allotropes - Correct Answer ✔✔ Forms of an element (the same element) with different
atomic/molecular structure
What is the approach to scientific knowledge? - Correct Answer ✔✔ Observation and
experiment
Scientific method - Correct Answer ✔✔ process for understanding nature by observing
nature and its behavior, and by conducting experiments to test our ideas.
What are the key characteristics of the scientific method? - Correct Answer ✔✔ -
Observation
- Formulation of hypotheses
- Experimentation
- Formulation of laws and theories
Observations (Data) - Correct Answer ✔✔ Descriptions about the characteristics or
behavior of nature
Hypothesis - Correct Answer ✔✔ Tentative interpretation or explanation of the
observations.
A good hypothesis is falsifiable.
- The results of an experiment may support a hypothesis or prove it wrong, in which
case the scientist must modify or discard the hypothesis.
Scientific Law - Correct Answer ✔✔ A brief statement that summarizes past
observations and predicts future ones
Law of Conservation of Mass - Correct Answer ✔✔ "In a chemical reaction, matter is
neither created nor destroyed"
, Scientific Theory - Correct Answer ✔✔ Model for the way nature is and tries to explain
not merely what nature does, but why. They are validated by experiments but can never
be proven conclusively because a flaw could be found.
Matter - Correct Answer ✔✔ Anything that occupies space and has mass and is
classified by its state (its physical form) and its composition (basic components that
make it up)
Can be classified as:
- solid
- liquid
- gas
Solid matter - Correct Answer ✔✔ Atoms or molecules pack close to each other in fixed
locations. They have fixed volume and rigid shape.
Crystallin - Correct Answer ✔✔
Amorphous - Correct Answer ✔✔ atoms or molecules do not have any long-range order
(i.e., glass and plastic)
Liquid matter - Correct Answer ✔✔ atoms or molecules pack about as closely as they
do in solid matter, they are are free to move relative to each other. Have fixed volume
but not fixed shape.
Gaseous matter - Correct Answer ✔✔ atoms or molecules have a lot of space between
them, are free to move relative to one another, and are compressible.
Pure substance - Correct Answer ✔✔ made up of only one component and its
composition is invariant. Either element or compound.
Element - Correct Answer ✔✔ substance that cannot be chemically broken down into
simpler substances
Compound - Correct Answer ✔✔ substance composed of two or more elements in fixed
definite proportions
Mixture - Correct Answer ✔✔ substance composed of two or more compound in
proportions that can vary from one sample to another. These are either heterogeneous
or homogeneous.
Heterogeneous mixture - Correct Answer ✔✔ the composition varies from one region of
the mixture to another (i.e., salt and sand)
Homogeneous mixture - Correct Answer ✔✔ made of multiple substances but appears
to be one substance
