Download Atomic Structure

Atomic Structure
OBJECTIVE: DESCRIBE THE
GENERAL STRUCTURE OF THE ATOM,
AND EXPLAIN HOW THE PROPERTIES
OF THE FIRST 20 ELEMENTS IN THE
PERIODIC TABLE ARE RELATED TO
THEIR ATOMIC STRUCTURES
Brainstorm
 What is matter?
 Give at least three examples. Give two examples of things that
are NOT matter, (Hint: thoughts).
 What is mass?
 What is an atom?
 Give at least three examples of things in this room that are
made of atoms.
 Is the air we breathe made of atoms? Explain your answer.
 What is a scientific theory?
The Basics
 Matter: Anything that takes up space and has a
mass.


Examples: a desk, a person, oxygen
Non Examples: feelings, thoughts
 Mass: A measure of how much matter an object
contains. Mass is related to weight.
 Element: A substance that can not be broken down
into a more simple substance.

Example: Gold, Oxygen, Carbon, Helium, Iron
The Basics
 Compound: A substance made of two or more
elements.

Example: CO2 , H2O
 Theory: A tested explanation with supporting
evidence. Can be changed, revised or disproved.

Example: Theory of Evolution-The change in physical traits in
a population over long periods of time.
Discussion
 Can scientist be proven wrong?
 Can science theories be changed?
 Is science a process that is continually worked on or
is it set in stone?
 Do many people usually contribute science
knowledge?
Activity
Discovering the Atom
 Aristotle:



Greek Philosopher
322 BC-384BC
Believed that four
elements made up all
things
Discovering the Atom: Dalton’s Contribution
 John Dalton



England 1776
Science Teacher
Atom looked like a ball
 Theory: All matter is
made up of individual
particles called atoms,
which cannot be divided.
Discovering the Atom: J.J. Thomas
 J.J. Thomas



1800
Discovered the electron
Plum pudding model
Discovering the Atom: Ernest Rutherford
 Rutherford:



1900 New Zealand
Discovered protons and
nucleus
Electrons move randomly
in space
Discovering the Atom: Niels Bohr
 Bohr:


1913
Electrons move in fixed
orbit around nucleus
Discovering the Atom: Schrodinger and
Chadwick
 Erwin Schrodinger:
 1926
 Describes motions of
electrons
 Leads to electron cloud
theory
 James Chadwick
 1932
 Confirms the existence of
neutrons
 Nucleus contains neutrons
and protons
The Atom – “Uncut” or “Indivisible”
 The smallest part or unit
of an element.
 Cannot be broken down
without losing its
properties
 Basic building block of
matter
 Makes up all physical
things
Parts of the Atom
Protons

Positively charged subatomic particle

Found in the nucleus
2. Neutrons

Neutrally or no charge

Subatomic particle found in
the nucleus
3. Electrons

Negative charge

Subatomic particle found
outside of nucleus

Nucleus

Dense center of the atom

Positive charge
1.
Atomic Number
 The number of protons for
any given element

All element of one kind have
the same number of protons


Example: All Hydrogen (H)
atoms have just one proton
Atoms of different elements
have different number of
protons
 Atomic number also gives
us the number of electrons
Discuss
 What charge are protons?
 What charge are electrons?
 Why do you think atoms have the same number of
protons and electrons?
Neutral Atoms
 The positive protons and
negative neutrons
balance out.
 This make the charge of
an atom neutral or zero.
 Draw an Example
Mass Number
 The number of protons
and neutrons found in
the nucleus

Protons + Neutrons =
Mass Number
Example: Carbon has a
mass number of 12
 This means there are 6
protons and 6 neutrons

 *Do the math
Practice Calculating the Number of Neutrons
Periodic Table
Bohr Model
 Looks like the solar
system
 Contains different energy
levels
 General Example:
Energy Levels and Orbitals
 Each ring of the Bohr Model is an energy level
 As you go further out from the nucleus the energy of
the electron becomes greater
 Electrons orbit around the nucleus much like the
earth orbits around the sun
Electron Configuration
 Configuration = Arrangement
 Desks in the classroom are arranged in a specific way
 Electrons are found in orbits around the nucleus.
This is their “electron configuration”
Energy Levels and Orbits
 Energy level 1
 Can contain only two electrons
 Energy levels 2 and 3
 Can contain up to eight electrons
 Energy levels must be filled before electrons can
move to the next shell
*Draw example labeling energy levels