1. Label the parts of an atom (electron cloud, electrons, nucleus, protons and neutrons)
Nucleus
Electron cloud
protons
neutrons
electron
2. Define an atom the smallest piece of an element that still represents that element
 The nucleus is made up of protons and neutrons. What is the charge of each
particle in the nucleus? Protons are positive (+); neutrons are neutral (0)
 The electron cloud is made up of electrons. What is the charge of this particle in
the electron cloud? Electrons are negative (-)
3. Define valence electron and how they can be determined? The outermost electron of
an atom that participates in chemical bonding. Valence electrons can be determined
by looking at the group number.
 How many valence electrons does Lithium (Li) have? 1 valence electron (it is in
group 1)
4. Define Mixture two or more substances that are physically blended together but are
not chemically bonded together.
 Identify three ways that a mixture can be separated
i. boiling
ii. magnetism
iii. filtration
5. Define heterogeneous and homogeneous mixtures. Give an example of each.
 Heterogeneous mixture a mixture in which substances are not evenly mixed
i. Example salad
 Homogeneous mixture a mixture in which two or more substances are evenly
mixed on the atomic level but are NOT bonded together.
i. Example chocolate milk
6. Identify which bond is covalent and which bond is ionic and define each.
A.
B.
A. Covalent Bond – a chemical bond formed when two atoms SHARE one or more pairs
of valence electrons.
B. Ionic Bond – a chemical bond formed when two atoms TRANSFER valence electrons
to form positively and negatively charged particles called ions
7. In picture B which type of ion does Sodium (Na) become? positive ion
8. In picture B which type of ion does Chlorine (Cl) become? Negative ion
9. Label the pH scale (acids, bases, neutral)
ACID
BASE
NEUTRAL
10.Define the following:
 Sublimation Change of state from a solid to a gas (without going through the
liquid phase)
 Deposition Change of state from a gas to a solid (without going through the
liquid phase)
 Melting Change of state from a solid to a liquid (thermal energy added)
 Freezing Change of state from a liquid to a solid (thermal energy removed)
 Boiling Causes change of state from a liquid to a gas
 Vaporization Change of state from a solid/liquid to a gas
 Condensation change of state from a gas to a liquid
11.Label the following phase change chart
A solid
B melting
C liquid
D boiling
E gas (vapor)
12.Define Endothermic Reaction A chemical reaction that absorbs thermal energy
 What happens to the temperature during and Endothermic Reaction? The
surroundings get cooler because thermal energy was absorbed
13.Define Exothermic Reaction A chemical reaction that releases thermal energy
 What happens to the temperature during an Exothermic Reaction? The
surroundings get warmer because thermal energy is released
14. List the 5 signs of a chemical reaction:
 Change in odor
 Formation of precipitate
 Change in color
 Absorb/release thermal energy
 Formation of bubbles
 Release light
15. Explain the difference between revolution and rotation.
Revolution – when a planet/moon travels once around the sun.
Rotation – when a planet/moon spins all the way around on its axis.
 What does revolution of Earth cause one year and contributes to the seasons
 What does rotation of Earth cause night and day
16.What two forces keep Earth revolving around the Sun? centripetal force (inertia and
gravity)
17.What force causes tides on Earth? The moons gravitational pull
18.What occurs due to the tilt of Earth on its axis? Different seasons
19.Define and illustrate a Lunar Eclipse and a Solar Eclipse.
Solar Eclipse- When the moon passes in front of the Sun and blocks most of suns light from
Earth
SUN
Lunar Eclipse – when the moon passes through Earth’s shadow/
SUN
20. Define a physical and chemical change. List an example of each.
 Physical Change any change in the form or appearance of matter
o Example ripping, breaking, dissolving, melting, blending
 Chemical Change when once substance changes into one or more substances
o Example burning, rusting (oxidation)
21.Label the following chemical equation.
REACTANT
YIELD
PRODUCT
22.Define Law of Conservation of Mass matter cannot be created nor destroyed
 Does the Law of conservation of Mass apply to the above equation? No, it is
unbalanced
23.Why does reactivity of elements decrease as you move from left to right across the
periodic table? Reactivity decreases because elements are trying to reach stability of 8
(or 2 ) valence electrons. The less valence electron’s an atom has the more reactive it
is.
24. Define Extinction When the last individual in a species dies.
 What could cause extinction
i. Unable to reproduce
ii. Unable to keep up with environmental changes
iii. No variation among a species
25.Define Adaptation An inherited trait that increases an organisms chance of surviving
and reproducing in a particular environment.
Give an example of an adaptation changing color or changing beak shape.