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WorksheetsCounting Atoms Review
Total questions: 20
Worksheet time: 38mins
Name
Class
Date
1.
How many elements are in C6H12O6?
a)
1
b)
2
c)
3
d)
4
2.
Element or compound?
O2
O2
a)
Element
b)
Compound
3.
Which of the following is a compound?
a)
Co
b)
O2
c)
C
d)
CO2
4.
Which is the correct formula for:
three hydrogen (H)
one sulfur (S)
four oxygen (O)
three hydrogen (H)
one sulfur (S)
four oxygen (O)
a)
H3SO4
b)
HSO4
c)
H4S3O
d)
H2O
5.
How many atoms are there TOTAL in:
H2SO4
H2SO4
a)
6
b)
5
c)
7
d)
3
6.
The red numbers in the image below represent ________
a)
subscripts
b)
coefficients
c)
I don't know, and don't want to try
d)
None of the answers are correct
7.
The blue numbers in the image below represent ________
a)
I don't know, and don't want to try
b)
coefficients
c)
subscripts
d)
none of the answers are correct
8.
What is the balanced equation when aluminum reacts with copper(II) sulfate to produce aluminum sulfate and copper?
a)
Al + Cu2S →Al2S + Cu
b)
2Al + 3CuSO4 → Al2(SO4)3 + 3Cu
c)
Al + CuSO4 → AlSO4 + Cu
d)
2Al + Cu2SO4 → Al2SO4 + 2Cu
9.
The substances at the beginning of a chemical equation are called the ____
a)
product
b)
yield
c)
chemical symbol
d)
reactants
10.
In the equation, 2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
11.
How many Valence Electrons does Argon have?
a)
2
b)
3
c)
8
d)
18
12.
How many valence electrons does Barium (Ba) have?
a)
1
b)
2
c)
5
d)
6
13.
Which of the following is an unbalanced equation?
a)
CaCO3 --> CaO + CO2
b)
PbO2 + 2H2-->2Pb + H2O
c)
2Na+ 2H2O-->2NaOH + H2
d)
CS2 + 2O2 --> CO2 + 2SO2
14.
What is a chemical equation?
a)
A short way to show a chemical reaction using symbols
b)
A way to explain a chemical reaction using words
15.
What is a valence electron?
a)
An electron in the outer most occupied energy level of an atom
b)
An electron that has properties similar to a transition metal
c)
Electrons with high reactivity
d)
Noble gases
16.
5CO2
How many molecules are there? How many elements?
How many molecules are there? How many elements?
a)
5 molecules, 2 elements
b)
2 elements, 5 molecules
c)
10 atoms, 5 elements
d)
15 elements, 2 molecules
17.
Name ALL the evidences that show a chemical reaction has occurred.
a)
color, gas, light
b)
light, precipitate, odor,
c)
color, gas, light, temperature, precipitate
d)
temperature, smell, light, conductivity, taste
18.
Which equation obeys the law of conservation of mass?
a)
H2 + O2 ------> H20
b)
C + 2H2 ----> CH4
c)
2Fe2O3 ------> 2O2 + 4Fe
19.
Black = Carbon (C)
White = Hydrogen (H)
What would be the formula for ethane?
White = Hydrogen (H)
What would be the formula for ethane?
a)
CH4
b)
CH6
c)
C2H2
d)
C2H6
20.
In a chemical reaction, everything to the rightof the arrow is called ______________.
a)
Products
b)
Yields
c)
Molecules
d)
Reactants
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