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Counting Atoms

Total questions: 35

Worksheet time: 23mins

Name
Class
Date
1.

How many Hydrogen atoms are in 4H2O?

a)

6

b)

8

c)

2

2.

How many Oxygen atoms are in H2O?

a)

1

b)

2

c)

0

d)

4

3.

How many Magnesium atoms are in 10MgCl2?

a)

10

b)

5

c)

20

4.
How many elements are in C6H12O6?
a)
1
b)
2
c)
3
d)
4
5.

How many atoms are there TOTAL in H2SO4 ?

a)

6

b)

5

c)

7

d)

3

6.

How many Sodium atoms are in 6NaCl?

a)

1

b)

12

c)

6

7.

How many atoms of Hydrogen are in this compound?

a)

1

b)

2

c)

3

d)

4

8.

How many Oxygen atoms are in Al₂(SO₄)₃?

a)

4

b)

12

c)

7

d)

24

9.

A subscript is the small number below the element symbol that tells the number of _______ of that element.

a)

atoms

b)

valence electrons

c)

protons

10.
Which of the following is a compound?
a)
Co
b)
O2
c)
C
d)
CO2
11.

How many Nitrogen atoms are in the in H2C3O4N5?

a)

2

b)

3

c)

5

12.

How many atoms of carbon (C) are in C6H12O6?

a)

3

b)

6

c)

12

13.

How many elements are present in this compound? (Careful!)

Mg2As3COHNi2

a)

2

b)

4

c)

6

d)

10

14.

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?

15.

H2SO4

a)

H = 2, S = 4, O = 4

b)

H = 2, S = 1, O = 4

c)

H = 8, S = 4, O = 4

16.

What is the smallest piece of matter that still has properties of that matter?

a)

element

b)

atom

c)

proton

17.

Negatively charged particle

a)

proton

b)

neutron

c)

electron

18.

Neutral charge particle

a)

proton

b)

neutron

c)

electron

19.

Positively charge particle

a)

proton

b)

neutron

c)

electron

20.

The central region of an atom where its neutrons and protons are is its

a)

nucleus

b)

electron cloud

c)

core

21.
An atom with atomic number 6 would have how many protons 
a)
6
b)
12
c)
3
d)
cannot be determined 
22.
Most of the mass in an atom is concentrated in the...
a)
electrons
b)
nucleus
c)
protons
d)
empty space
23.
What does the nucleus consist of?
a)
Protons + Electrons
b)
Neutrons + Electrons
c)
Atoms
d)
Protons + Neutrons
24.

What does the 1.00794 stand for?

a)

mass number

b)

atomic number

c)

average atomic mass

d)

number of protons

25.
What is the number of protons that the element in this image contain?
a)
14
b)
7
c)
15
d)
18
26.
If an atom has 10 protons, 10 neutrons, and 10 electrons, what is the mass of the atom?
a)
10
b)
20
c)
30
27.

If the mass number of this chlorine atom is 36, how many neutrons does it have?

a)

17

b)

18

c)

19

d)

can't be determined

28.

What is the atomic number of this atom shown in the Bohr model?

a)

11

b)

12

c)

13

d)

can't be determined

29.

What is the mass number of the atom shown in the Bohr model?

a)

11

b)

12

c)

23

d)

Can't be determined

30.

Beryllium has how many protons?

a)

4

b)

9.0122

c)

2

31.
Valence electrons are the...
a)
Innermost electrons
b)
Middle electrons
c)
Outermost electrons
d)
Any electrons
32.

How many valence electrons does carbon have?

a)

4

b)

5

c)

6

d)

7

33.
Which group has the greatest number of valence electrons?
a)
1
b)
14
c)
18
d)
16
34.
a)
2
b)
3
c)
5
35.
a)
12
b)
7
c)
8
d)
14