Reading the information from an element
• Every box in the periodic table represents an element and has at least
3 parts to it
1. Atomic
number
1. Atomic number: The number of protons in the
nucleus.
2. Symbol
2. Symbol: The one- or two-letter “short name” for
the element.
3. Atomic
mass
3. Atomic mass: How heavy the element is on
average. Mass of protons + neutrons.
1
H
1.00794
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Protons are always the same as the atomic number
Name: Hydrogen
Atomic Number: 1
Atomic Mass: 1.00794
Atomic Symbol: H
Number of Protons: 1
Number of Neutrons: 0
Number of Electrons: 1
Calculated by subtracting the atomic number from the
rounded atomic mass:
(Atomic mass) – (Atomic number) = (1.00794) – (1) = 0
Same as the number of protons in atoms with no charge
(rounded to 1)
16
S
32.066
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Protons are always the same as the atomic number
Name: Sulfur
Atomic Number: 16
Atomic Mass: 32.066
Atomic Symbol: S
Number of Protons: 16
Number of Neutrons: 16
Number of Electrons: 16
Calculated by subtracting the atomic number from the
rounded atomic mass:
(Atomic mass) – (Atomic number) = (32.066) – (16) = 16
Same as the number of protons in atoms with no charge
(rounded to 32)
83
Bi
208.58
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Protons are always the same as the atomic number
Name: Bismuth
Atomic Number: 83
Atomic Mass: 208.58
Atomic Symbol: Bi
Number of Protons: 83
Number of Neutrons: 126
Number of Electrons: 83
Calculated by subtracting the atomic number from the
rounded atomic mass:
(Atomic mass) – (Atomic number) = (208.58) – (83) = 126
Same as the number of protons in atoms with no charge
(rounded to 209)