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Counting atoms in chemical formulas

Total questions: 45

Worksheet time: 23mins

Name
Class
Date
1.
How many Sodium (Na) are in 6NaCl?
a)
1
b)
12
c)
6
2.
How many Magnesium are in 10MgCl2?
a)
10
b)
5
c)
20
3.

How many different elements are in C6H12O6?

a)
1
b)
2
c)
3
d)
4
4.
How many atoms are there TOTAL in:
H2SO4
a)
6
b)
5
c)
7
d)
3
5.
Number of N in (NH₄)₂CrO₄
a)
1
b)
2
c)
8
d)
16
6.
(Element or Compound)
       C2H8
a)
Element
b)
Letters
c)
Numbers
d)
Compound
7.
A subscript is the small number below a(n) ________ that tells the number of _______ of that element.
a)
element symbol; atoms
b)
atom; element symbol
c)
subscript; protons
d)
compound; elements
8.
How many Oxygen atoms are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
9.
Number of H in 3(NH₄)₂CrO₄
a)
4
b)
2
c)
8
d)
24
10.
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
11.
How many Oxygen atoms are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
12.
How many total atoms are in this compound?
H2C3O4N5
a)
5
b)
14
c)
15
d)
19
13.
If there is no subscript, there is/are ______ atom(s) of that element.
a)
0
b)
2
c)
only 1
d)
1 million
14.
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
15.
How many atoms of aluminum are on each side of the following equation: 4Al + 3O--> 2AlO3
a)
2
b)
6
c)
1
d)
4
16.
How many O's are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
17.
How many Oxygen are in H2O?
a)
1
b)
2
c)
0
d)
4
18.
How many Hydrogen are in 4H2O?
a)
6
b)
8
c)
2
d)
4
19.
What are the small numbers that go AFTER an element symbol called? Like the 2 in H2O ?
a)
subscript
b)
symbol
c)
coefficient
d)
superscript
20.
What is the number that is in FRONT of a formula called? Like the 3 in 3H2O
a)
subscript
b)
coefficient
c)
symbol
d)
superscript
21.
How many atoms are there TOTAL in:
H2SO4
a)
6
b)
5
c)
7
d)
3
22.
The small number to the right of an elemental symbol  ( H2) is called?
a)
 a subscript 
b)
a coefficient 
c)
a variable 
d)
a divisor 
23.
The smallest building block of matter is the......................
a)
compound 
b)
molecule 
c)
atom
d)
fluid
24.
There are over 100 different kinds of atoms these different atoms are known as ....................
a)
elements 
b)
mixtures
c)
chemical bond 
d)
chemistry 
25.
When a molecule is made up of more than two different elements ( Example CO2)  we call this .......................
a)
a mixture 
b)
atom
c)
a compound 
26.
How many Aluminum are in Al2O3?
a)
3
b)
2
c)
5
27.
How many O's are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
28.
How many Elements are in the compound C2H8O ?
a)
2
b)
1
c)
3
d)
0
29.

In this compound structure of (ethanol) alcohol, how many Hydrogen atoms are there?

a)
2
b)
4
c)
6
d)
8
30.

How many different elements are present in this compound?
Mg2As3COHNi2

a)
2
b)
4
c)
6
d)
10
31.
How many Magnesium are in 10MgCl2?
a)
10
b)
5
c)
20
32.

How many molecules(formula units) are in 10MgCl2?

a)
10
b)
5
c)
20
33.
How many total atoms are in the compound C2H8O ?
a)
11
b)
2
c)
8
d)
1
34.
How many atoms are there TOTAL in:
H2SO4
a)
6
b)
5
c)
7
d)
3
35.

How many atoms are of Carbon are in one formula unit of this compound?
H2C3O4N5

a)
2
b)
3
c)
4
d)
5
36.
How many TOTAL atoms are in this compound?
H2C3O4N5
a)
5
b)
14
c)
15
d)
19
37.
What is the number of protons that the element in this image contain?
a)
14
b)
7
c)
15
d)
18
38.

How many atoms are present if there is no subscript following the element symbol?

a)

0

b)

2

c)

only 1

d)

1 million

39.

Are there any compounds on the periodic table?

a)

yes there are many

b)

no because only elements are on the periodic table

c)

I think they are?

d)

there is no way to tell

40.
Is the following an element or a compound?
C2H8
a)
element
b)
compound
41.
How many elements are in the following?
C2H8O
a)
2
b)

11

c)
3
d)
0
42.
How many total atoms are in the following?
C2H8O
a)
11
b)
2
c)

3

d)
10
43.
Which of the following is a compound?
a)
Co
b)
O2
c)
C
d)
CO2
44.

How many Hydrogens are in 4H2O?

a)
6
b)
8
c)
2
d)
4
45.
What is a coefficient?
a)
The small number on the right of the chemical symbol.
b)
The large number to the left of a formula.