ChemQuest 8: Answer Key
Name: ___________________________
Date: _______________
Period: _____
Information: Structure of the Atom
Note the following symbols: (they are not to scale)
= proton (positive charge)
= electron (negative charge)
= neutron (no charge)
The following three diagrams are hydrogen atoms:
1
1
2
1
H
H
3
1
H
The following three diagrams are carbon atoms:
12
6
13
6
C
(6 protons, 6 neutrons)
Notice the type of notation used for atoms:
C
(6 protons, 7 neutrons)
A
Z
14
6
C
(6 protons, 8 neutrons)
X
X = chemical symbol of the element
Z = “atomic number”
A = “mass number”
12
6
1
1
C , 136 C, and 146 Care notations that represent isotopes of carbon.
3
H , 21 H and 1 H are notations that represent isotopes of hydrogen.
The part of the atom where the protons and neutrons are is called the nucleus.
Critical Thinking Questions
1
2
3
1. How many protons are found in each of the following: 1 H ? in 1 H ? in 1 H ?
1 proton in each
1
2. How many neutrons are found in each of the following: 1 H ? in
1
1
H :0
2
1
H :1
3
1
2
1
H? in 31 H ?
H :2
3. How many electrons are found in each of the following:
1 electron in each
1
1
H ? in 21 H ? in 31 H ?
4. What do all hydrogen atoms have in common? (Hint: Think in regards to subatomic particles.)
All hydrogen atoms have the same number of protons and electrons.
5. What does the mass number tell you?
Protons plus neutrons
6. What does the atomic number tell you?
Number of protons
7. How would you, in your own words, define the term isotope?
Isotopes are atoms of the same element that have a different number of neutrons.
8. How does one isotope of carbon differ from another isotope of carbon?
Each isotope of carbon has a different number of neutrons.
9. How is one isotope of carbon similar to another isotope of carbon?
All isotopes of carbon have the same number of protons and the same number of electrons.