WorksheetsTopic 9 Review for the Topic 8 & 9 Test
Total questions: 14
Worksheet time: 7mins
What is formed when a sodium atom (Na) and a chlorine atom (Cl) react chemically to form salt (NaCl)?
an element
a molecule
an electron
a neutron
Which of the following is possible evidence that a chemical reaction has occurred? Chose ALL that apply.
bubbles are released
color change
change in smell/taste
a precipitate forms
A chemical change happens when ____________.
glass breaks
bread bakes in the oven
ice cream melts
electricity flows through a wire
During a chemical reaction, what happens to the total mass of the substances involved?
the mass increases
the mass deacreases
the mass stays the same
the mass is doubled
Consider the following formula for hydrogen peroxide: H2O2.
What is the coefficient?
0
1
2
4
Consider the following formula for hydrogen peroxide: H2O2.
How does the number of hydrogen atoms compare to the number of oxygen atoms?
they are the same
there is more hydrogen
there is more oxygen
there is not enough information provided
What coefficient for O2 demonstrates the law of conservation of mass?
CH4 + __O2 → CO2 + 2H2O
1
2
3
4
What does the Law of Conservation fo Mass state?
Matter cannot be created or destroyed in a chemical reaction.
New atoms are created in the products of chemical reactions.
The total mass of the materials increases during a chemical reaction.
The mass of the reactants is always greater than the mass of the products.
What happens to a pile of lumber as it burns?
It is completely destroyed.
It is completely changed into heat energy.
It changes into other types of matter and energy.
It remains unchanged.
If two reactants have a mass of 5g and 10g and they undergo a chemical change, what will the mass of the products be?
5g
10g
15g
50g
An example of a synthetic material is ______________.
plastic
wood
wheat
stone
Substances that are made by humans through chemical processes are called _____________ materials.
natural
fake
synthetic
organic
Two objects that are made of the same substance also have the same mass. Which object has more total thermal energy?
The colder object.
The hotter object.
They must always have the same total thermal energy.
If a chemical reaction absorbs more energy from the surrounding environment than it gives off, it must be ___________.
endothermic
exothermic
nuclear
irrefutable
