Standard Atomic Notation
Mass Number: Fluorine
has a total of 19 protons
and neutrons
19
9
F
Atomic Number:
Fluorine has 9 protons
Therefore fluorine has 19 – 9 = 10 neutrons
Since atoms have no net charge it must have as many electrons as it does protons.
Activity: What does Standard Atomic
Notation Tell Us?
Standard
Atomic Number
12
6
C
65
30
Zn
Name of
Element
Atomic Number
Mass Number
Number of
Electrons
Number of
Protons
Number of
Neutrons
carbon
6
12
6
6
6
sulfur
16
calcium
nitrogen
51
23
115
49
16
40
7
20
14
V
In
molybdenum
96
40
42
18
Atomic and Mass Numbers
Atomic Number
9
Ion charge(s)
F
Symbol
Name
Mass Number
1-
Fluorine
19.00
Atomic Mass
19
Atomic Number = the number of protons in the nucleus
Mass Number = the whole number sum of the of protons and neutrons in the nucleus
Atomic Mass = the mass of the atom weighted across its isotopes
Atomic and Mass Numbers
Atomic Number
1
Ion charge(s)
H
Symbol
Name
Mass Number
1+
Hydrogen
1.0079
Atomic Mass
1
Atomic Number = the number protons in the nucleus
Mass Number = the whole number sum of the of protons and neutrons in the nucleus
Atomic Mass = the mass of the atom weighted across its isotopes
Representing Atoms with Diagrams
• We represent atoms using Bohr-Rutherford models
• What is a Bohr-Rutherford model?
• What information is captured in a Bohr-Rutherford model?
Phosphorus atom
15 p+
16 n0
15 protons
16 neutrons
15 electrons
Representing Atoms with Diagrams
inner most
electron
orbital:
can hold up to
2 electrons
third electron
orbital: can
hold up to 8
electrons
x p+
x protons in
the nucleus
y n0
y neutrons in
the nucleus
second electron
orbital: can hold
up to 8 electrons
NOTE: # protons may = # neutrons
NOTE: # protons = # electrons
Representing Atoms with Diagrams
Hydrogen
Beryllium
Helium
Lithium
Boron
Carbon
Periodic Table of Elements
1
1
18
2
13
2
3
3
4
5
6
7
6
7
4
6
7
8
9
10
11 12
14 15
16
17