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WorksheetsChemistry Retest Practice
Total questions: 52
Worksheet time: 44mins
Name
Class
Date
1.
How many different elements are represented in the compound Na2CO3?
a)
1
b)
2
c)
3
d)
4
2.
Italian salad dressing is a
a)
heterogeneous mixture
b)
homogeneous mixture
c)
pure Substance
d)
compound
3.
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
4.
How many hydrogen atoms are in this chemical formula: 2H2O?
a)
4 hydrogen atoms
b)
1 hydrogen atom
c)
2 hydrogen atoms
d)
3 hydrogen atoms
5.
How many oxygen atoms are in this chemical formula: H3PO4?
a)
7 oxygen atoms
b)
4 oxygen atoms
c)
3 oxygen atoms
d)
1 oxygen atoms
6.
How many Magnesium atoms are in 3MgCl2?
a)
3
b)
5
c)
1
d)
6
7.
The law of conservation of mass states that
a)
matter is created
b)
matter is destroyed
c)
matter is neither created nor destroyed
d)
matter does not change
8.
Is this equation balanced?
a)
Yes
b)
No
c)
Not enough information
9.
What is the law of conservation of mass?
a)
Matter changes when reacted or changed.
b)
The mass of all reactants are changed during a physical or chemical change
c)
The mass of the reactants is the same as the mass of the products
d)
The mass of the products is different than the mass of the reactants.
10.
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.
11.
The building block of all matter is the
a)
Mixture
b)
Atom
c)
Element
d)
Substance
12.
This is made up of one or more of the SAME kind of atom:
a)
Element
b)
Mixture
c)
Compound
d)
Matter
13.
Copper is a mixture.
a)
True
b)
False
14.
Pure water (H2O) is
a)
a pure substance
b)
a mixture
c)
an element
d)
a heterogeneeous mixture
15.
An example of a compound would be
a)
hydrogen gas (H2)
b)
heterogeneous
c)
sodium chloride (NaCl)
d)
oxygen gas (O2)
16.
Which is Chemical Equation is Balanced?
a)
CH₄+O₂------CO₂+2H₂O
b)
H₂+O₂-----2H₂O₄
c)
4Al+3O₂-----2Al₂O₃
17.
How many nitrogen atoms does NH3 have?
a)
1
b)
2
c)
3
d)
4
18.
Which Chemical Equation is Balanced?
a)
CH₄+O₂------CO₂+2H₂O
b)
H₂+O₂-----2H₂O₄
c)
4Al+3O₂-----2Al₂O₃
19.
Bob puts 200 grams of ice into a pitcher with 900 grams of water. He gets distracted and comes back later to find that the ice has melted in the water. How many grams of water does Bob now have in the pitcher?
a)
200 g
b)
700 g
c)
1,100 g
20.
Endothermic reactions...
a)
release energy
b)
explode
c)
take in energy
d)
have higher energy in their reactants than the products
21.
Exothermic reactions
a)
have higher energy in their products than their reactants
b)
release energy
c)
get cold
d)
are synthesis reactions
22.
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.
23.
When CaCO3 is heated, it forms CaO and CO2. Which of these statements best describes the mass of the products if 100 g of CaCO3 is heated?
a)
The difference in the products’ masses is equal to the mass of the CaCO3
b)
The sum of the products’ masses is less than the mass of the CaCO3
c)
The mass of each product is equal to the mass of the CaCO3
d)
The sum of the products’ masses equals the mass of the CaCO3
24.
Each column in the periodic table is called a
a)
period
b)
group
c)
cluster
d)
unit
25.
The atomic number tells you what?
a)
number of electrons
b)
number of protons
c)
number of neutrons
d)
both electrons and protons in an atom.
26.
Which group of the periodic table is composed of inert (not reactive) gases?
a)
alkali metals
b)
alkaline earth metals
c)
halogens
d)
noble gases
27.
Elements which are shiny, conduct electricity and heat are called
a)
metal
b)
nonmetal
c)
metalloid
d)
nonexistent
28.
The atoms along the staircase are called
a)
metals
b)
nonmetals
c)
metalloids
d)
noble gases
29.
What does the 1.00794 stand for?
a)
Hydrogen
b)
atomic number
c)
atomic mass
d)
atomic explosion
30.
Particles in an atom that are neutral and have no charge are
a)
negatrons
b)
electrons
c)
neutrons
d)
protons
31.
What is the atomic mass equal to?
a)
the number of protons
b)
the number of protons and neutrons
c)
the number of neutrons
d)
the number of protons and electrons
32.
In the modern periodic table elements are arranged by:
a)
atomic mass
b)
atomic number
c)
valence electrons
d)
number of isotopes
33.
atoms bond so that they have 8 valence electrons
a)
octet rule
b)
conservation of mass
c)
valence law
d)
catalyst
34.
the chemicals present BEFORE a chemical reaction
a)
reactants
b)
products
c)
ions
d)
valence electrons
35.
a process that transforms one set of substances into another by breaking existing chemical bonds and forming new ones
a)
chemical reaction
b)
valence electron
c)
octet rule
d)
conservation of mass
36.
Which of these is NOT a sign that a chemical reaction occurred?
a)
a phase change
b)
heat released
c)
gas produced
d)
a color change
37.
In the following chemical equation:
2Na + Br → 2NaBr
2Na + Br → 2NaBr
a)
the number of sodium (Na) atoms decreases
b)
the atoms that make up the products are the same atoms that make up the reactants
c)
the sodium (Na) and bromine (Br) atoms have more mass after the reaction
d)
atoms are created in the formation of the new compound (NaBr)
38.
During photosynthesis, plants turn water and carbon dioxide into glucose and oxygen:
carbon dioxide + water → glucose + oxygen
Which of the following would be considered a PRODUCT of photosynthesis?
carbon dioxide + water → glucose + oxygen
Which of the following would be considered a PRODUCT of photosynthesis?
a)
carbon dioxide
b)
water
c)
oxygen
d)
sunlight
39.
Carbon
a)
element
b)
compound
40.
Carbon Dioxide
a)
element
b)
compound
41.
Sugar
a)
element
b)
compound
42.
Vinegar
a)
element
b)
compound
43.
CO2
a)
sugar
b)
vinegar
c)
carbon dioxide
d)
water
44.
How many electrons would be in an atom of fluorine?
a)
9
b)
18
c)
18.998
d)
10
45.
A liquid has a . . .
a)
Definite shape and definite volume
b)
A definite shape but no definite volume
c)
No definite shape or definite volume.
d)
A definite volume but no definite shape
46.
Which one of the following would be a correct unit for density?
a)
g/kg
b)
g/cm
c)
g/cm3
d)
g
47.
Which of the following represents a chemical change?
a)
tearing paper in half
b)
melting ice into water
c)
roasting a marshmallow
d)
chopping wood
48.
Matter which has no definite shape or volume is known as a
a)
solid
b)
liquid
c)
gas
49.
What is an atom?
a)
A name for children
b)
The smallest building block of Earth
c)
The rubrics cube
d)
The stuff that builds up mankind
50.
Which elements have the most similar chemical properties?
a)
K and Na
b)
K and Ca
c)
K and Cl
d)
K and S
51.
Why is water classified as a compound?
a)
Because it is an element, which consists of only one type of atom.
b)
Because it is a substance, which can easily be separated.
c)
Because it is a substance composed of two or more kinds of atoms bonded together.
d)
Because it is an unevenly mixed solution, or a heterogeneous mixture.
52.
The mass of the products in a chemical reaction is the same as the mass of the reactants in the reaction. Which law best describes this statement?
a)
The Law of Conservation of Angular Momentum
b)
The Law of Superposition
c)
The Law of Conservation of Matter
d)
The Law of Entropy
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