The Periodic Table
Research Biology
Mr. Luis A. Velázquez
Dynamic Periodic Table
Democritus 400 B.C.
Our word atom therefore comes
from atomos, a Greek word meaning
uncuttable.
Democritus reasoned that if matter
could be infinitely divided, it was also
subject to complete disintegration from
which it can never be put back
together.
The three main subatomic
particles that form an atom are
protons, neutrons, and electrons.
The center of the atom is called the
nucleus.
( + ) Protons
( - ) Electrons
(O) Neutrons
Subatomic Particles
Element Symbols
•All elements have a symbol.
•The symbol will always be a letter or two.
Example: C, Ca
•The symbol will always begin with a capital
letter.
• If the symbol has a second letter it will always
be lower case.
Atomic Number
A unique number for each
element that equals the
number of protons in an atom
of that element.
Atomic Mass Number
A unique number for each
element that equals the number
of protons and neutrons present
in the nucleus of the atom.
In other words is the sum of the
nucleus of the atom. (P+N=mass)
Practice 83
Bismuth
Bi
209
What is the atomic mass? 209
What is the atomic number? 83
What is the number of protons?83
What is the number of neutrons?
126
Elements
A substance that cannot be
broken down in to simpler
substance.
There 112 elements in the
periodic table.
Elements
112 total elements
92 natural elements
20 artificial or synthetic elements
man-made elements.
Elements
25 needed for life
4 Are essential elements for life
they make 99% of living tissue
C, H , O, N
1 Element essential for life
State of Matter of Elements
1. Solid is a substance that has definite
shape and definite volume.
2. Liquid is a substance that has no definite
shape and has definite volume.
3. Gas is a substance that has no definite
shape and no definite volume.
1. Some elements are found in nature as gases.
2. There are 11 elements as a gas state.
3.Gases can be classify as stable or unstable
gases.
Unstable gases: (5) gases
H, N, O, F, Cl
Stable gases: (6) gases
He, Ne, Ar, Kr, Xe, Rn
Liquids
1. Some elements are found in nature as liquids.
2. There are 2 elements as liquid state.
The two liquids are:
Br, Hg
Summary
There are 112 elements in the periodic table,
the are subdivide into:
1.Gases (11) H,N,O,Cl,F,He,Ne,Ar,Kr,Xe,Rn
2.Liquids (2) Br, Hg
3.Solids (99) Li, C,Mg,Mn,Co, Au,Ag,Cu,Fe…
Understanding the atom
•The atomic number is the number of protons
•The atomic mass number is the number of protons
and neutrons. The sum of the nucleus of the atom.
6
Atomic number = Protons = 6
C
12
Atomic mass = P + N = 12
Understanding the atom
17
Atomic number = Protons = 17
Cl
35
Atomic mass = P + N = 35
P= 17
N= 18
E= 17
Understanding the atom
11
Atomic number = Protons = 11
Na
23
Atomic mass = P + N = 23
P= 11
N= 12
E= 11
Understanding the atom
Atomic number = Protons = 7
7
N
14
P= 7
N= 7
E= 7
Atomic mass = P + N = 14
Understanding the atom
20
Atomic number = Protons = 20
Ca
40
Atomic mass = P + N = 40
P= 20
N= 20
E= 20