Transcript The Periodic Table of Elements and Atoms…

The Periodic Table of Elements
and Atoms…
History first…
Alchemy
Robert Boyle
John Dalton
Dmitri Mendeleev
Jons Berzelius
Alchemy:
one of the earliest forms of
chemistry.
Scientists try (unsuccessfully) to turn
metals of low value (iron or lead) into
gold.
Though they were unsuccessful, they
contributed knowledge to the chemical
world. For example how changes affect
matter.
Robert Boyle…
Considered the first real
chemist. He introduced the first
definition of an element as a
pure substance that cannot be
broken into simpler substances
by chemical means.
John Dalton…
introduced the idea that each
element was made up of
a
different kind of atom.
Atomic Structure…
An atom is made up of three basic parts:
protons, neutrons, and electrons. The
protons which have a positive charge [+]
and the neutrons which have no charge,
form the nucleus in the center of the atom.
The electrons which have a negative
charge [-], move sporadically around the
nucleus.
Draw this model on your paper
•Electrons are negatively charged particles that
have a very low mass. There are an equal
number of electrons as there are protons.
•Protons are positively charged particles found
in the nucleus. There are an equal number of
protons as there are electrons.
•Neutrons, also found in the nucleus, have no
electrical charge. They are neutral. They have
about the same mass as a proton.
•The nucleus is the central core of an atom
that contains most of the mass of an atom
because it contains both the neutrons and
protons.
Each atom has an equal number
of protons and electrons.
Because the negative charge of
the electrons balances the
positive charge of the protons,
atoms are neutral.
Dmitri Mendeleev…
arranged the elements into a systematic
chart or table called the Periodic Table
of Elements. Today’s periodic table of
elements based on Mendeleev’s version
groups the elements by similar
properties. It gives the symbol, the
atomic number, and the atomic mass of
each element.
Jons Berzelius…
introduced a system of abbreviation
for the elements, which is still in use
today. The symbol was determined
by using the first letter of the
element’s name or Latin name and
capitalizing it and in most cases
added another letter, which remained
lower case.
An example of how an atom is represented on the
Periodic Table of Elements.
1
H
Atomic Number-tells you the
amount of protons and electrons.
Atomic Symbol
Hydrogen
1.0079
Full Name
Atomic Mass
How do you know how many protons,
electrons, and neutrons each atom has?
• The atomic # tells you how many protons and
electrons there are in each atom.
• You need a formula to calculate the amount of
neutrons. The formula is:
Atomic mass(large #)
minus the Atomic #(smaller #)
equals the amount of neutrons.
or
AM – A# = neutrons
Practice finding the amount of Protons, Electrons,
and Neutrons:
1. Aluminum
2. Oxygen
Practice continued
3. Mercury
4. Hydrogen
The Periodic Table of Elements
Each box on the table represent an atom. Start
seeing each element as a different atom.
The boxes are arranged in order of increasing
atomic number (protons/electrons) as you move
from left to right.
The boxes are arranged into a grid of periods
(Horizontal rows) and groups (Vertical
columns)
Two different
numbering systems!
• One of the numbering systems:
– Numbers the groups(columns) 1-18!
• The other numbering system:
– Divides the table of elements into two categories:
• Main Group Elements- the first two
groups(columns) and last six groups(columns). We
notate the group number with the letter “A”. (Ex.,
2A)
• Transition Metals-the ten groups(columns) in the
center. We notate the groups number with the letter
“B”. (Ex., 3B)
•
List the numbers as they would appear at the top of
each column on the P.T.o.E.:
1_ 2_
___ ___ ___ ___ ___ __
___ ___ ___ ___ ___ ___ ___ ___ ___ ___
_1a_ 2a_
___ ___ ___ ___ ___ __
___ ___ ___ ___ ___ ___ ___ ___ ___ ___
Let’s talk organization!
The elements are divided into 3
categories: Metals, Metalloids, and
Nonmetals. We use the “Zig-Zag” line as
a reference.
The metals are to the left of the “Zig-Zag”
line except: Hydrogen-it’s a nonmetal
The metalloids are on the “Zig-Zag” line.
except: Aluminum, it’s all metal!
The nonmetals are to the right of the
“Zig-Zag line. except: Hydrogen-even
though it is located to the left it is still a
nonmetal
Memorizing the states of each atom at room
temperature helps use the periodic table as a tool!
• There are 11 gases and 2 liquids at room
temperature:
Gases
hydrogen-
Neon
Liquids
Bromine
Helium-
Xenon
Mercury
Nitrogen
Argon
Oxygen
Krypton
Fluorine
Radon
Chlorine
The six gases located in the group
#18(8a) are called the noble gases.
These gases are different and set apart
from other gases because they do not
combine easily if at all with other
atoms/elements.
Acids and Bases to be discussed on
Bonding Notes!!!
The End
I hope you enjoyed!!!