Science review 1
Give an example of a chemical change (reaction)
Random Answers that may include: Burning stuff, changing the molecules permanently
Random answers that may include: bending, cutting, or melting something, but not changing the molcules in a permanent way.
Is this an example of a molecule or an atom?
Gold
atom
Which of these is a molecule?
NaCl (salt)
H2O (water)
Aluminum
Oxygen
NaCl (salt) and H2O (water)
What occurs at the boiling point of a substance?
a. the substance changes from a gas to a solid
b. the substance changes from a liquid to a solid
c. the substance changes from a solid to a liquid
d. the substaqnce changes from a liquid to a gas
What does the Law of Conservation of Mass say?
Matter is never created or destroyed, but transformed into a different form.
What is the process by which plants make energy from the sun?
photosynthesis
What are the PRODUCTS of photosynthesis?
oxygen and glucose (sugar)
What is the name of this molecule?
CO2
Carbon Dioxide
What is the name of this common molecule?
C6H12O6
Glucose
Which would be an example of chemical potential energy: (x3)
a. a spring compressed
b. a ball rolling down a hill
c. a child sitting at the top of a slide
d. powder on the tip of a match
d. powder on the tip of a match
Where do all living things on the earth originally get their energy from?
The sun
What is it called when the earth heats up too much and the glaciers start to melt?
Global Warming or Global Climate Change
x 7
What is evaporation?
a . gas turns to liquid
b. solid turns to liquid
c. liquid turns to gas
d. water turns to ice
c. liquid turns to gas
What are the 7 evidences of a chemical change?
X5 points
Odor
Color
Precipitate
Gas
Temperature change (sometimes light and sound)
x5
Frozen orange juice is place in a bowl. After a few minutes it begins to melt. What type of change has occurred?
a. chemical
b. melting
c. physical
d. mixture
c. physical
What is the unit for energy?
JOULE
x3
Which of the following is a physical change?
a. lighting a match b. rusting metal
c. baking a cake d. making koolaid
d. making koolaid
x6
Which is an example of a chemical change?
a. melting ice
b. dissolving salt in water
c. hammering metal into a thin sheet of foil
d. burning a piece of paper
d. burning a piece of paper
Which of these is NOT a greenhouse gas?
water vapor
carbon dioxide
methane
oxygen
oxygen
Which list correctly identifies the elements that make up a water molecule?
a. oxygen, hydrogen, nitrogen
b. oxygen, hydrogen, carbon
c. oxygen, hydrogen, oxygen
d. hydrogen, oxygen, hydrogen
d. hydrogen, oxygen, hydrogen
C6H22O6
34
How many atoms of hydrogen are in 3 molecules of H2O?
6
Only 10% of the energy is used when going up each level of a trophic pyramid.
Where does 90% of the energy go when going up the trophic pyramid?
5X points
90% is lost as heat to the enviornment
What type of potential energy is food or fuel?
chemical potential
Which of the following are physical properties?
density
melting point
flammability
explosive
reactivity
density and melting point
x2 Points
In which situation is a chemical reaction not taking place
a. salt dissolving in water
b. rusting of an old car in a junk yard
c. burning gasoline in a car
d. digestion of food in our body
a. salt dissolving in water
Which of the following is the LARGEST atom?
Hydrogen
Oxygen
Lithium
What is the formula for carbon dioxide?
CO2
How many hydrogen atoms are in 4 molecules of NH4?
16
x4
Which is the best example of a chemical change?
a. fireworks exploding
b. cutting paper
c. crushing a can
d. melting snow
a. fireworks exploding
What are the reactants of photosynthesis?
x3 points
Carbon dioxide, water, and sunlight
Look at a periodic table to find this answer...
How many protons are in an atom of carbon?
x3 points
6
What is the charge of a neutron?
neutral=no charge
x2
Which material is a pure element or atom?
a. alcohol
b. copper
c. salt
d. water
b. copper