Download Atomic Structure

Atomic Structure
The Atom
 Smallest form of an element that still retains
that elements properties
 Basic building block of matter
 Made of:
Protons
Neutrons
Electrons
The Atom
Composed of:
Nucleus
Electron Cloud
The Nucleus
Positively charged
Protons and neutrons
Protons – positively
charged
Neutrons – neutrally
charged
Neutrons act like glue
The Electrons
 Negatively charged
 Occupy the “Electron cloud”
surrounding the nucleus
 Arranged into shells or orbitals
 Electrons are NOT moving in
perfect orbits around the nucleus.
The electron movement is
unpredictable
 Cloud gives us approximate
location of where electrons are
Subatomic Particles
Location
Charge
Mass
Protons
Nucleus
Positive (+)
1 amu
Neutrons
Nucleus
Neutral
1 amu
Electrons
Electron Cloud
Negative (-)
0.00054 amu
Special Fact
Number of protons
determines the identity of
the element
Electron cloud takes up
99.9999999% of the
volume of the atom
Properties of Atoms
Atomic Number
Mass Number
Average Atomic Mass
INSIDE THE SQUARES…
Atomic Number
 Number of protons in the nucleus of an atom
 Each element has its own specific atomic number
 In a NEUTRAL ATOM, this is also the number of
electrons
(Average) Atomic Mass
 An average mass of each of the different isotopes
found for that element in nature
 For example, Chlorine has 2 different isotopes
 Each one has 17 carbons and a different number of
neutrons (This is what an isotope is. More on that later)
 If you take the average atomic mass of every
single chlorine atom that
exists, the average mass
will be 35.453 amu
Mass Number
 Mass number is the mass of a SPECIFIC isotope of an
atom.
 It is the SUM of the protons and neutrons in the nucleus
 Mass Number = (# of neutrons) + (# of protons)
Mass Number = Atomic Mass
It is not the average unless we say AVERAGE
 How do we find # of
neutrons?
So how do I know what the
Mass Number is?
I will tell you. One of two ways:
1) Give you the mass number or the neutrons in a table.
If I don’t give it to you, get the rounded # off the PT
2) Tell you in the symbol.
A)Isotope Notation:
B)Isotope Name:
Sodium-23
Figuring out some element parts…
Element
Boron-11
Symbol
Atomic #
Protons
Neutrons
6
6
Mass #
B
Carbon -12
Magnesium-23
12
Copper-64
29
23
35
20
Figuring out some element parts…
Element
Symbol
Atomic #
Protons
Neutrons
Mass #
Boron-11
B
5
5
6
11
Carbon -12
C
6
6
6
12
Magnesium-23
Mg
12
12
11
23
Copper-64
Cu
29
29
35
64
?
?
?
20
?
?
TED Talks
 https://www.ted.com/talks/just_how_small_is_an_atom
 Ideas: atom smasher balloon (like a particle accelerator used
to actually measure properties of atoms)
 https://www.giftofcuriosity.com/penny-balloon-diy-atom-
smasher/#_a5y_p=2296171