Atoms & Isotopes
Name __________________
An atom is the smallest particle of an element. Atoms are made up of subatomic particles: protons,
neutrons and electrons.
Subatomic Particle
Proton
Neutron
Electron
Mass
(amu- atomic mass unit)
1
1
0
Charge
Location
+1
0
-1
nucleus
nucleus
In orbits around nucleus
An atom is neutral (no charge); the number of protons equal the number of electrons.
The mass number of the atom is the sum of the protons and neutrons.
The atomic number is the number of protons. This number will identify the atom.
Isotopes are atoms with the same atomic number but different number of neutrons.
Complete the missing information. The first one is completed as an example.
Atomic Structure
Protons
Neutrons
Atomic
Calculations
Atomic # = #P
#P = #e
Electrons
Mass # = #P + #N
Identity
Determine the
atomic number
and identify the
atom by using the
periodic table.
Isotope
Symbol-Mass
Isotope Notation
Mass
#P
X
#Protons = 3
Atomic # = 3
Li
Li-7
#electrons = 3
#neutrons = 4
Mass # = 7
Lithium
#Protons = _____
Atomic # = _____
#electrons = _____
#neutrons = _____
Mass # = _____
F-19
7
3
Li
Atomic Structure
Atomic
Calculation
Protons
Neutrons
Electrons
Atomic # = #P
#P = #e
Identity
Determine the
atomic number
and identify the
atom by using the
periodic table.
Isotope
Symbol-Mass
Isotope Notation
Mass
#P
X
Mass # = #P + #N
#Protons = _____
Atomic # = _____
#electrons = _____
#neutrons = _____
Mass # = _____
#Protons = _____
Atomic # = _____
#electrons = _____
#neutrons = _____
14
6
Mass # = _____
Questions (use a periodic table):
1.
Write the isotope notation for an atom with 7 protons and 7 neutrons. ________
2.
Write the isotope of the atom that has 14 protons and a mass of 28. ________
3.
Write the isotope of the atom that has 19 protons and 20 neutrons. ________
4.
What atom has 92 electrons? ______
5.
U-238 has _______ more neutrons than U-235.
6.
All carbon isotopes have _____ protons.
7.
C-12 and C-14 are isotopes. What is another isotope of carbon? ______
8.
How many neutrons are in Cl-36? _____
9.
What is the mass of Au-197? _____
10. Which 2 subatomic particles make up the mass of an atom? ___________ & __________
C
KEY
Atoms & Isotopes
Name __________________
An atom is the smallest particle of an element. Atoms are made up of subatomic particles: protons,
neutrons and electrons.
Subatomic Particle
Proton
Neutron
Electron
Mass
(amu- atomic mass unit)
1
1
0
Charge
Location
+1
0
-1
nucleus
nucleus
In orbits around nucleus
An atom is neutral (no charge); the number of protons equal the number of electrons.
The mass number of the atom is the sum of the protons and neutrons.
The atomic number is the number of protons. This number will identify the atom.
Isotopes are atoms with the same atomic number but different number of neutrons.
Complete the missing information. The first one is completed as an example.
Atomic Structure
Protons
Neutrons
Atomic
Calculations
Atomic # = #P
#P = #e
Electrons
Mass # = #P + #N
Identity
Determine the
atomic number
and identify the
atom by using the
periodic table.
Isotope
Symbol-Mass
Isotope Notation
Mass
#P
X
#Protons = 3
Atomic # = 3
Li
#electrons = 3
#neutrons = 4
Mass # = 7
Li-7
7
3
F-19
19
9
Li
Lithium
#Protons = 9
Atomic # = 9
9P
10N
F
#electrons = 9
#neutrons = 10
Mass # = 19
Fluorine
F
Atomic Structure
Atomic
Calculation
Protons
Neutrons
Electrons
Atomic # = #P
#P = #e
Identity
Determine the
atomic number
and identify the
atom by using the
periodic table.
Isotope
Isotope Notation
Symbol-Mass
Mass
#P
X
Mass # = #P + #N
#Protons = 5
B
Atomic # = 5
#electrons = 5
#neutrons = 6
B-11
11
5
C-14
14
6
B
Boron
Mass # = 11
#Protons = 6
C
Atomic # = 6
6P
8N
#electrons = 6
#neutrons = 8
Mass # = 14
Carbon
Questions (use a periodic table):
1.
Write the isotope notation for an atom with 7 protons and 7 neutrons.
147N
2.
Write the isotope of the atom that has 14 protons and a mass of 28. Si-28
3.
Write the isotope of the atom that has 19 protons and 20 neutrons. K-39
4.
What atom has 92 electrons? Uranium
5.
U-238 has 3 more neutrons than U-235.
6.
All carbon isotopes have 6 protons.
7.
C-12 and C-14 are isotopes. What is another isotope of carbon? C-13
8.
How many neutrons are in Cl-36? 19
9.
What is the mass of Au-197? 197
10. Which 2 subatomic particles make up the mass of an atom? Protons & Neutrons
C