Download atomic structure intro ISCI

Atomic Structure
Learning Goals
 Identify and describe particles which
comprise atoms.
 Compare atoms and contrast forces
inside.
 Determine subatomic particles from
atomic number and mass number.
Bellringer
 What is an atom?
 What does an atom look like?
Body Essentials
Protein
Lipids (Fat)
Carbohydrate
Macromolecules that aid in human performance.
To understand their functions we must understand their structure.
Structure of the Atom
 In order to understand atoms, we need
to understand the idea of electric
charge.
 We know of two different
kinds of electric charge
and we call them positive
and negative.
Electric charge in matter
 We say an object is electrically neutral when
its total electric charge is zero.
Nucleus- small
dense center of the
atom.
protons and neutrons
Electron Cloudouter part of atom
where the electrons
lie.
Inside an atom
 The mass of the nucleus
determines the mass of an
atom!!
 protons and neutrons are
much larger and more
massive than electrons.
 In fact, a proton is 1,836
times heavier than an
electron! WOW!
Proton and Neutron
weigh almost the same
Force inside atoms
 Electrons are bound
to the nucleus by the
attractive force
between electrons (-)
and protons (+).
Force inside atoms
 What holds the nucleus
together?
 There is another force
that is even stronger
than the electric force.
 We call it the strong
nuclear force.
How are atoms of various
elements different?
 The atoms of different
elements contain different
numbers of protons in the
nucleus.
 Because the number of
protons is so important, it
is called the atomic
number.
SUPER SUPER IMPORTANT!
 Protons define the element!
 CAN’T CHANGE NUMBER OF PROTONS!
Hydrogen ALWAYS has 1 proton
Helium ALWAYS has 2 protons
Chlorine ALWAYS has 17 protons
What info can we gather from
the Periodic Table?
6
C
12.011
Atomic Number =
# of protons / # of electrons
Symbol of element
Atomic Mass =
(# of protons) + (# of neutrons)
Check for Understanding!
How many protons,
neutrons, and electrons
are in iron given the
periodic table?
Answer:
26 protons, 26 electrons,
and 30 neutrons
Calculating P, N, and E
Symbol
Mass
Proton
B
Electron
6
24
Pb
Neutron
11
207
You may need the Periodic Table to fill in this chart