Final Exam Study Guide 4
1. What part of the atom is found outside the nucleus?
ANS: Electrons in an electron cloud
2. Which of the following is a chemical change?
a. iron is denser than limestone
b. burning wood results in ash and smoke
c. the boiling point of alcohol is lower than that of water
ANS: b
3. If a peach tree is self-pollinating and susceptible to a certain disease that can kill it, what
are the chances that its offspring will be susceptible to the disease?
ANS: When a true breeding plant self pollinates, all the offspring will have the
same traits as the parent.
4. If you throw a football 25 meters to a friend, what force is acting on the ball without
touching it?
ANS:
1. Air resistance: the force that opposes the motion of objects through air
2. Gravity: a force of attraction between objects that is due to their mass.
5. What are three examples of simple machine?
Type
Example
Activity
1. Pulley - How Stuff
Works
A pulley is a simple
machine that uses
grooved wheels and a
rope to raise, lower or
move a load.
Pulleys
2. Lever - Enchanted
Learning animations
A lever is a stiff bar that
rests on a support
called a fulcrum which
lifts or moves loads.
Levers
3. Wedge - pictures
using LEGO bricks
A wedge is an object
with at least one
slanting side ending in
a sharp edge, which
cuts material apart.
Wedges
4. Wheel & Axle Activity using pencils and
thread spools
A wheel with a rod,
called an axle, through
its center lifts or moves
loads.
Wheels
5. Inclined Plane pictures using LEGO
bricks
An inclined plane is a
slanting surface
connecting a lower
level to a higher level.
Inclined
Planes
6. Screw - Activity using
pencil and paper in a new
way
A screw is an inclined
plane wrapped around a
pole which holds things
together or lifts
materials.
Screws
6. Why haven’t astronauts traveled to all the planets in our Solar System?
ANS: NASA astronauts have been in space, off and on, for 45 years. Except for a few quick trips to the moon,
though, they've never spent much time far from Earth. Deep space is filled with protons from solar flares,
gamma rays from newborn black holes, and cosmic rays from exploding stars. A long voyage to Mars, with no
big planet nearby to block or deflect that radiation, is going to be a new adventure. Therefore, we simply do not
have the technology we need to protect the individuals who would go to these planets from harm. The amount
of time to get to some planets and back is very long. Gliese 581d is just a short 20 year hop away (once we
master that travel at the speed of light thing). And by the theory of time dilation, those who chose to make the
leap would barely age during the trip. Of course, such news on an eco-blog can only lead to one obvious
question:
7. What are the elements that are found in stars?
10 Most common elements in the Sun, which is a star
Element Abundance (% of total
Abundance
number of atoms)
(% of total mass)
Hydrogen
91.2
71.0
Helium
8.7
27.1
Oxygen
0.078
0.97
Carbon
0.043
0.40
Nitrogen
0.0088
0.096
Silicon
0.0045
0.099
Magnesium
0.0038
0.076
Neon
0.0035
0.058
Iron
0.030
0.014
Sulfur