WorksheetsChemistry Review
Total questions: 40
Worksheet time: 33mins
Name
Class
Date
1.
Students react baking soda & vinegar.
Which of the following would provide the evidence that the number of atoms present before a chemical reaction is equal to the number of atoms present after the chemical reaction?
Which of the following would provide the evidence that the number of atoms present before a chemical reaction is equal to the number of atoms present after the chemical reaction?
a)
The mass of the plastic bag, baking soda, and vinegar before the reaction was equal to the mass after the reaction.
b)
Bubbles were produced during the reaction, which meant that a gas was being produced.
c)
The plastic bag did not change in any way, indicating that it was not involved in the reaction.
d)
The mass of the baking soda was exactly equal to the mass of the vinegar used to create the chemical reaction.
2.
Matter can not be created nor destroyed: it can only be
a)
Destroyed a little bit
b)
Invisible
c)
Transformed, changed
d)
None of the above
3.
Suppose a reaction were to happen in an open container in a lab. During the reaction, the scientist observes the chemicals bubble, and produce a gas. During the analysis the scientist notices that the reactants weighed 20 g when he started, and the product weighed 18 g. Explain what happened.
a)
His chemical reaction defied the law of conservation of mass
b)
The product destroyed mass during the reaction
c)
The reactants created matter during the reaction
d)
The gas that was produced was not able to be weighed since the container was open.
4.
A chemical reaction is balanced when
a)
both sides have the same elements
b)
Both sides have the same number of atoms
c)
Same subscripts
d)
Same coefficients
5.
How many oxygen atoms are in this chemical formula?
a)
6 oxygen atoms
b)
2 oxygen atoms
c)
3 oxygen atoms
d)
4 oxygen atoms
6.
In a reaction A + B ----> C, reactant A has 5g and product C has 9g. How many grams does reactant B should have?
a)
4g
b)
5g
c)
9g
d)
14g
7.
Endothermic reactions...
a)
release energy
b)
explode
c)
take in energy
d)
have higher energy in their reactants than the products
8.
Exothermic reactions
a)
have higher energy in their products than their reactants
b)
release energy
c)
get cold
d)
are synthesis reactions
9.
Molecule
a)
A group of atoms bonded together
b)
Basic unit of a chemical element
c)
Coefficient
d)
Subscript
10.
Balance this equation.
_CF4 + _Br2 -- _CBr4 + _F2
_CF4 + _Br2 -- _CBr4 + _F2
a)
2,1,2,1
b)
1,2,2,1
c)
1,2,1,2
d)
2,2,2,2
11.
Balance this equation-
__P4 + __O2 --> __P2O3
__P4 + __O2 --> __P2O3
a)
it is already balanced
b)
2, 1, 3
c)
1, 2, 3
d)
1, 3, 2
12.
Italian salad dressing is a
a)
heterogeneous mixture
b)
homogeneous mixture
c)
pure Substance
d)
compound
13.
Milk is a
a)
Heterogeneous mixture
b)
Homogeneous mixture
c)
Element
d)
Compound
14.
A heterogeneous mixture in which some of the particles settle out of the mixture upon standing is called a
a)
solution
b)
colloid
c)
solvent
d)
suspension
15.
The substance that dissolves is called the
a)
solvent
b)
solution
c)
solute
d)
unsaturated
16.
The substance that dissolves the solute is called the
a)
solution
b)
solvent
c)
saturation
d)
solute
17.
A mixture of two or more substances; very small dissolved particles are spread evenly throughout the mixture
a)
solvent
b)
solute
c)
suspension
d)
solution
18.
This appears on the left side of a chemical formula, and represents how many molecules there are.
a)
An Atom
b)
The Subscript
c)
A Molecule
d)
The Coefficient
19.
Is this equation balanced?
a)
Yes
b)
No
c)
Not enough information
20.
Is this equation balanced?
a)
Yes
b)
No
c)
Not enough information
21.
The building block of all matter is the
a)
Mixture
b)
Atom
c)
Element
d)
Substance
22.
This is made up of one or more of the SAME kind of atom:
a)
Element
b)
Mixture
c)
Compound
d)
Matter
23.
DIFFERENT kinds of atoms chemically combined to form a substance called a(n)
a)
Mixture
b)
Element
c)
Compound
d)
Substance
24.
An example of a compound would be
a)
hydrogen gas (H2)
b)
heterogeneous
c)
sodium chloride (NaCl)
d)
oxygen gas (O2)
25.
Which element has 31 protons ?
a)
Gallium
b)
Germanium
c)
Gadolinium
d)
Polonium
26.
Oxygen’s atomic number is 8. This means that an oxygen atom must have
a)
8 electrons
b)
8 protons
c)
8 neutrons
d)
a mass number of 8
27.
What is the role of an electron in an atom?
a)
Electrons live inside the nucleus and carry a neutral charge.
b)
Electrons circle the nucleus and have a positive charge.
c)
Electrons circle the nucleus and have a negative charge.
d)
Electrons live inside the nucleus and have a negative charge.
28.
Whose atomic model said electrons orbit the atom like planets orbit the sun
a)
Einstein
b)
Thomson
c)
Bohr
d)
Dalton
29.
Whose atomic model was called the "plum pudding model?"
a)
Dalton
b)
Rutherford
c)
Thomson
d)
Schrodinger
30.
What should you do if you break glass in the lab?
a)
Tell the teacher
b)
Clean it up
c)
Get your partner to clean it up for you.
d)
Hide it
31.
What does the nucleus consist of?
a)
Protons + Electrons
b)
Neutrons + Electrons
c)
Atoms
d)
Protons + Neutrons
32.
What is the atomic mass of "F," Fluorine?
a)
9
b)
18
c)
17
d)
19
33.
How many the electrons does "Al," aluminum, have?
a)
5
b)
10
c)
13
d)
3
34.
What are the 3 particles that make-up the atom?
a)
protons, neutrons, and isotopes
b)
neutrons, isotopes, and electrons
c)
positives, negatives, and electrons
d)
protons, neutrons, and electrons
35.
The __________ ___________ of an atom makes up most of the volume of an atom?
a)
Electron cloud
b)
Energy cloud
c)
Outer ring
d)
subatomic particles
36.
The smell your dog makes after eating to much people food.
a)
Chemical Change
b)
Physical Change
37.
Baking a cake by mixing flour, sugar, chocolate powder, eggs, and milk, and then heating them in the oven.
a)
Chemical Change
b)
Physical Change
38.
A change in the size, shape, or state of matter.
a)
chemical change
b)
physical change
c)
chemical reaction
d)
electron change
39.
A change in which NEW substances are formed.
a)
Chemical change
b)
Physical change
c)
Casual change
d)
Formal change
40.
In the equation, 2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
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