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Worksheets2017-2018 Chemistry Pre-Assessment_UR6-12
Total questions: 33
Worksheet time: 3hrs 45mins
Name
Class
Date
1.
How many elements are in one molecule of glucose (C6H12O6)?
a)
1
b)
3
c)
6
2.
When a molecule is separated into its component parts, it forms...
a)
compounds
b)
atoms
c)
protons
d)
ions
3.
Sugar is added to water and the mixture is stirred. Which observation is evidence that the sugar dissolved in the water?
a)
Less sugar is visible
b)
The water is cloudy
c)
The sugar turned into crystals
d)
Bubbles formed in the water
4.
Chemical formulas for several common substances are listed in the table.
Why does hydrogen (H) have a different subscript in each substance?
Why does hydrogen (H) have a different subscript in each substance?
a)
The subscript indicates the number of hydrogen atoms in each substance.
b)
The subscript indicates the number of mixtures that the hydrogen is forming.
c)
The subscript indicates the number of compounds that the hydrogen is forming.
d)
The subscript indicates whether the hydrogen is forming a compound or a mixture.
5.
What is the smallest unit of an element that still retains the element’s properties?
a)
a proton
b)
a crystal
c)
an atom
d)
a molecule
6.
Which is the best example of a heterogenous mixture?
a)
sugar
b)
brass
c)
salad
d)
saltwater
7.
Calcium carbonate (CaCO3) is considered a compound because it is made up of two or more..
a)
molecules
b)
elements
c)
gases
d)
solids
8.
Which is the best description of one particle of table salt (NaCl)?
a)
atom
b)
compound
c)
element
9.
When table salt (NaCl) is produced, which of the following best describes the actions of the sodium (Na) and chlorine (Cl) atoms?
a)
Sodium atoms replace chlorine atoms.
b)
Sodium and chlorine atoms mix together.
c)
Sodium atoms dissolve in chlorine atoms.
d)
Sodium and chlorine atoms bond chemically.
10.
On the periodic table, in which group is the metalloid silicon found?
a)
Group 3
b)
Group 14
c)
Group 15
11.
Which best describes elements that are shiny, malleable, ductile, and good conductors of heat and electricity?
a)
halogens
b)
metals
c)
metalloids
d)
nonmetals
12.
Which element has 7 valence electrons?
a)
hydrogen (H)
b)
fluorine (F)
c)
lead (Pb)
13.
Sodium reacts with water. Which element is most likely to have a similar effect to sodium if it is exposed to water?
a)
carbon
b)
oxygen
c)
lithium
14.
Which property determines the chemical reactivity of an element?
a)
atomic structure
b)
solubility
c)
density
d)
volume
15.
Johnny is trying to identify a sample of a highly reactive nonmetal. With which elements would his sample most likely be found on the periodic table?
a)
neon (Ne) and radon (Rn)
b)
fluorine (F) and bromine (Br)
c)
silicon (Si) and phosphorous (P)
d)
sodium (Na) and magnesium (Mg)
16.
How are elements on the periodic table organized by their properties?
a)
in groups
b)
by masses
c)
in periods
17.
What best describes the reactivity of alkali metals?
a)
Reactivity increases left to right across a period.
b)
Reactivity decreases left to right across a period.
c)
Reactivity increases down a group.
18.
Why are certain elements placed into the same column on the periodic table?
a)
They have the same number of protons in their nuclei.
b)
They have the same number of electrons in their nuclei.
c)
They have the same number of electrons in their outer energy level.
19.
Which element is the least reactive?
a)
carbon
b)
helium
c)
hydrogen
d)
iodine
20.
Which is the best term to describe a chemical reaction that absorbs heat energy?
a)
catalytic
b)
exothermic
c)
endothermic
21.
Max combines baking soda and vinegar in a flask. Which is the most likely reason Max should place a balloon over the mouth of the flask before he mixes the two substances?
a)
to prevent any gas formed as a product from escaping during the reaction
b)
to prevent any liquid used as a reactant from escaping during the reaction.
c)
to prevent any powder used as a reactant from escaping during the reaction.
d)
to prevent any liquid formed as a product from escaping during the reaction.
22.
Which best describes a chemical reaction occurring?
a)
boiling water
b)
color change
c)
ice melts
23.
When water boils, water vapor is produced and escapes into the air.Which best describes this change?
a)
melting
b)
freezing
c)
physical change
d)
chemical change
24.
John and Lisa collected a sample of ocean water and placed it in a jar. Within a couple of days,the water had evaporated and salt was visible at the bottom of the jar. This is an example of a...
a)
physical change
b)
chemical change
c)
solute being dissolved
d)
new substance being formed
25.
Two identical containers each hold one liter of water. One container is kept at room temperature as a liquid. The other container is placed in a freezer and kept as a solid. Which property is most likely to be the same in both states of matter?
a)
density
b)
mass
c)
shape
d)
volume
26.
In a chemical reaction, what is the best description of a molecule’s movement when the temperature decreases?
a)
movement decreases
b)
movement increases
c)
movement stays the same
27.
Which term describes the relationship between the mass and volume of asubstance?
a)
density
b)
solubility
c)
specific heat
d)
melting point
28.
Which best describes the solid that forms when two liquids combine in a chemical reaction?
a)
gas
b)
energy
c)
precipitate
29.
Which best explains why conservation of mass should be studied in a closed system?
a)
to prevent the loss of any reactants.
b)
to prevent contamination of the products.
c)
to prevent the release of any gases produced.
d)
to prevent the absorption of heat from the outside.
30.
Which equation is balanced according to the Law of Conservation of Mass?
a)
NaCl + Mg → MgCl2+ Na
b)
2NaCl + Mg → MgCl2+ Na
c)
2NaCl + Mg → MgCl2+ 2Na
31.
One molecule of carbon dioxide (CO2) combines with one molecule of water (H2O) to make one molecule of carbonic acid. According to the Law of Conservation of Mass, how many atoms of carbon should be in the carbonic acid?
a)
1
b)
2
c)
3
32.
When 5 grams of silver nitrate are added to a 50 gram solution of potassium chloride, 2 grams of silver chloride form in the solution as a precipitate. After the reaction, the total weight of the solution is 55 grams. Which evidence from the experiment supports the law of conservation of mass?
a)
The final weight of the product equals the weight of the reactants.
b)
The final weight of the product is less than the weight of the reactants.
c)
The weight of the precipitate is less than the amount of silver nitrate.
d)
The weight of the precipitate is greater than the amount of silver nitrate.
33.
The conversion of 7.0 grams of carbon monoxide and 7.5 grams of nitrogen monoxide using 3.0 grams of platinum catalyst is shown.
Which best represents the total mass of carbon dioxide and nitrogen gases produced in this process?
Which best represents the total mass of carbon dioxide and nitrogen gases produced in this process?
a)
3.5 grams
b)
10.5 grams
c)
14.5 grams
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