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Worksheets8th Grade Chemistry Review
Total questions: 19
Worksheet time: 57mins
Name
Class
Date
1.
A researcher wants to experiment with an element that reacts like phosphorus (P) but has a greater atomic mass. Which element should there searcher select for the experiment?
a)
Nitrogen(N)
b)
Sulfur(S)
c)
Arsenic (As)
d)
Silicon(Si)
2.
For an investigation, a student measures the speed of a cart as it rolls down a ramp. The student then records the data in the table. Which of these best explains the student's data?
a)
The speed of the cart decreases as the cart rolls down the ramp because of friction between the cart and the ramp.
b)
The speed of the cart increases as the cart rolls down the ramp because the force acting on the cart is greater than the force of gravity.
c)
The speed of the cart increases as the cart rolls down the ramp because of forces acting on the cart are unbalanced.
d)
The speed of the cart decreases as the cart rolls down the ramp because of the forces acting on the cart are balanced.
3.
A scientist spilled a few drops of dilute hydrochloric acid on a lab table. For safety purposes, the scientist sprinkled some baking soda onto the spill. Which observation would provide the best evidence that a chemical reaction occurred?
a)
The baking soda and hydrochloric acid combined, and bubbles formed.
b)
The baking soda absorbed the hydrochloric acid.
c)
Some of the baking soda dissolved in the hydrochloric acid.
d)
The hydrochloric acid evaporated, leaving only the baking soda.
4.
Four students raced toy cars on a track. The mass and the acceleration of each car is recorded in the table. Which toy car had the greatest applied force?
a)
1
b)
2
c)
3
d)
4
5.
When trying to identify an unknown element, a scientist determines what other elements the unknown element reacts with chemically. Which property of the unknown element determines the other elements it reacts with?
a)
The total number of neutrons in the unknown element
b)
The total number of particles in the nucleus of the unknown element
c)
The number of protons in the nucleus of the unknown element
d)
The number of valence electrons in the unknown element
6.
An atom has 25 protons, 30 neutrons, and 25 electrons. What is the charge of the atom's nucleus?
a)
+25
b)
+30
c)
-25
d)
-30
7.
How many atoms of oxygen are in a molecule of glucose (C6H12O6)?
a)
12
b)
6
c)
18
d)
24
8.
The chemical equation shown represents a reaction that produces fuel for certain cars. Which substance represented in this equation is classified as an element?CO + H2O --> CO2 + H2
a)
CO
b)
H2O
c)
CO2
d)
H2
9.
Many processes occur in the digestive system. Which process is best classified as a physical change?
a)
Saliva converting the starch molecules in crackers into simple sugars
b)
Digestive enzymes breaking down proteins into smaller fragments
c)
Bacteria converting lactose into simple sugars in the intestines
d)
Teeth grinding an almond into smaller pieces in the mouth
10.
Some students in a chemistry lab conducted an investigation in which they added four different solid substances to separate beakers of water. They stirred the mixtures for one minute and then recorded their observations in the table. Which substance most likely caused a new substance to be formed when mixed with water?
a)
Substance 1
b)
Substance 2
c)
Substance 3
d)
Substance 4
11.
When a space shuttle was launched, the astronauts onboard experienced an acceleration of 29.0 m/s2. If one of the astronauts had a mass of 60.0 kg, what net force in newtons did the astronaut experience?
a)
660
b)
2.07
c)
1740
d)
1240
12.
Based on its chemical formula, which of the following substances is an organic compound?
a)
Urea, CH4N2O
b)
Ammonium Sulfide, (NH4)2S
c)
Saline, SiH4
d)
Sodium Chloride, NaCl
13.
A student uses a magnet to move a 0.025 kg metal ball. The magnet exerts a force of 5 N, which causes the ball to begin moving. What is the acceleration of the ball when it begins to move?
a)
200 m/s2
b)
0.125 m/s2
c)
5 m/s2
d)
5.025 m/s2
14.
Coal contains carbon and other elements. Carbon dioxide forms when coal burns in the presence of oxygen. Which of these is the best evidence that a chemical reaction occurs when coal burns?
a)
The shape f the coal changes.
b)
Oxygen is present.
c)
A new substance is produced.
d)
Coal is made up of more than one element.
15.
The atoms of a certain element each contain 11 protons and 1 valence electron. Which statement correctly identifies this element and describes its chemical reactivity?
a)
The element is sodium, and it is highly reactive.
b)
The element is fluorine, and it is not very reactive.
c)
The element is sodium, and it is not very reactive.
d)
The element is fluorine, and it is highly reactive.
16.
A bus travels 20 km in 30 minutes. What is the average speed of the bus? (hint: look at the units of measurement in the answer!!!!!)
a)
20 km/h
b)
30 km/h
c)
40 km/h
d)
50 km/h
17.
An atom of a certain element has 36 protons, 36 electrons, and a mass number of 84. At room temperature this element is a very stable gas. How many neutrons are in this atom?
a)
58
b)
72
c)
120
d)
48
18.
The periodic table is organized into groups and periods of elements. The characteristics of a certain group of elements are listed. Which of these elements is in this group?
a)
Lithium
b)
Strontium
c)
Aluminum
d)
Silicon
19.
Which of these formulas contain equal numbers of nitrogen atoms?
a)
Formulas I and III
b)
Formulas I and IV
Formulas I and IV
Formulas I and IV
c)
Formulas II and III
Formulas II and III
Formulas II and III
d)
Formulas I, II, and V
Formulas I, II, V
Formulas I, II, V
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