Download Atoms and Elements ppt - Mrs. Hoenshell Science 2016

Periodic Table
Mrs. Hoenshell
Bellwork
On a quarter sheet of paper,
draw and label the parts of an
atom. Add an explanation for
each part. Explain how we know
atoms exist.
You have only 5 minutes.
Atomic Structure
November 14
Objective: “I will be able to identify the parts of an atom
and learn the symbols and the electrons, protons and
neutrons for the first 20 elements in the periodic table.”
Classwork: Intro to the Periodic Table
Essential Questions: How does the structure of matter
and the properties of elements affect the uses of
materials? How can science gain new technology by
learning more about matter?
What is
Matter?
What is
Matter?
• anything that has
mass and takes
up space
• matter is made
up of atoms
What is an Atom?
What are Subatomic
Particles?
What is an Atom?
• the smallest unit into which
matter can be divided
• building blocks of all
matter
• comprised of a nucleus (at
it’s center) and an electron
cloud (surrounding the
nucleus)
What are Subatomic
Particles?
• made up of sub-atomic
particles
• smaller than an atom
• protons
• neutrons
• electrons
How is the Atom’s Center Formed?
Protons and neutrons are grouped together to
form the “center” or nucleus of an atom
Notice that the electrons are not apart of the nucleus
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+
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+ +
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Early Atom Models:
What is the
Rutherford Model?
• mostly empty
space
• small, positive
nucleus
• contained protons
and electrons
scattered around
the outside
Early Atom Models:
What is the Bohr
Model?
• electrons move in
definite orbits
around the
nucleus
Modern Atom
Model: What is the
The Electron Cloud
Model?
• sometimes called
the wave model
• spherical cloud of
varying density
• varying density
shows where an
electron is more
or less likely to be
What are
Protons?
++ +
+ + +
+ +
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-
-
+
-
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• positively charged
particles (+)
• help make up the nucleus
of the atom
• equal to the atomic
number of the atom
• contribute to the atomic
mass
• equal to the number of
electrons
What are
Neutrons?
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++ +
+ + +
+ +
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-
• neutral particles;
have no electric
charge
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-
• help make up the
nucleus of the
atom
• contribute to the
atomic mass
What are
Electrons?
++ +
+ + +
+ +
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-
-
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• negatively charged particles
(-)
• found outside the nucleus of
the atom in the electron
orbits/levels
• each orbit/level can hold a
maximum number of
electrons
• 1st orbital = 2 electrons
• 2nd orbital = 8 electrons
• 3rd orbital = 8 electrons
What are
Valence
Electrons?
• found in the outermost
energy level of the
electron cloud (called
the valence shell)
• involved in bonding
• determine the
chemical properties of
an element
How are
Atoms
Described?
• atomic number = number
of protons
• in a neutral atom, the #
of protons = the # of
electrons
• atomic mass= the
number of protons + the
number of neutrons
How are Atoms
Described?
What is Atomic
Number?
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-
+
++
• the number
of protons in
the nucleus
of an atom
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What would be the atomic number of
this atom?
What is the
Atomic Mass?
What would be the
atomic mass of this
atom?
• the total number of
protons and neutrons
in an atom’s nucleus
• expressed in Atomic
Mass Units (amu)
each proton or
neutron has a mass
of 1 amu
Building Atoms
Atoms
Carbon
Beryllium
Oxygen
Lithium
Sodium
Protons
Neutrons
Electrons
Building Atoms
Using the whiteboard and the proton, neutron,
and electron pieces, build the following atoms,
and determine their atomic and mass numbers.
Atoms
Carbon
Beryllium
Oxygen
Lithium
Sodium
Protons
6
4
8
3
11
Neutrons Electrons
6
6
5
4
8
8
4
3
12
11