Transcript Notes09

Conceptual Physics
Study Notes & Questions: Atoms (Chap. 9+)
One of our tasks in discussing the universe is to develop a common
vocabulary so we can speak with one another. Thus, we have terms to
Atoms are the basic build blocks of matter in the universe.
Atoms are composed of which 3 common subatomic particles? Which
has the least mass? What electric charge does each have? How are
they arranged to form an atom (draw a picture)?
An element is a single type of atom—it can not be broken down into
simpler substances by chemical means. Atomic nuclei can have
different numbers of protons and neutrons. What determines which
element a given atom is? Which particle(s) contribute the most mass
to an element?
The atomic number of an element is…?
The atomic weight of an element is…? (FYI: the integer sum of
neutrons and protons in an atom is called its mass number.)
Two or more atoms stuck together form a …? The energy that holds
atoms together is called a …? (p187)
A material made of the same type of atoms, or molecules held
together by chemical bonds, is called a…? (p187)
Materials that consist of different atoms and molecules found
together, but are not sharing chemical bonds are called a …? (p188)
What is Avogadro’s principle? (p188) Why do you think a helium
balloon works? (Hint, the atomic weight of helium is much less than
normal air, which primarily consists of nitrogen and oxygen.)
10) What are the four phases of matter? What distinguishes them? (Hint:
think about volume and shape.) (p189)
For a solid, distinguish crystals, glasses and polymers. (p191)
12) A material whose atoms/molecules can flow freely around on another
is called a …? (p194)
13) Temperature is the average molecular translational kinetic energy of a
material. (Suggestion: understand what this means, it will help your
conceptual understanding of the universe a great deal!) Phase
change in a material is usually accompanied by temperature change.
Describe the sequence of going from solid to gas. (p195) What terms
are used to denote the phase changes of materials? (p196)
14) What is Brownian motion? (p197) Describe what is going on at the
molecular level.
15) What is surface tension? (p193) The average speed of air molecules
at room temperature is about 1000 miles per hour (444 m/sec). If
molecules evaporating off a liquid surface shoot off at ~1000 mph,
what does that tell you about the “weak” intermolecular forces holding
molecules in liquid form?
16) If you were hit upward by a mass (similar to your own) at 1000 mph,
you would rise about 6 miles, neglecting air resistance, before falling
back to earth. On your way down, what insight would this event give
you in regard to why all the air on our planet doesn’t collapse into a
thin layer at the surface?