Download Structure of the Atom

Bellringer
 Read page 510 then answer the following questions:
 What significant changes occurred in the atomic model
between Figure 5A and Figure 5B?
 What significant changes occurred in the atomic model
between Figure 5B and Figure 5C?
 What significant changes occurred in the atomic model
between Figure 5C and Figure 5D?
Structure of the Atom
Scientific Shorthand
•
C
•
Al
•
N
•
O
•
CO2
•
H2O
• All of these are symbols for an element or a compound
• It is easier to write C rather than Carbon or H2O rather than
Dihydrogen Oxide
Atomic Components
 Element – matter that is composed of one type of atom
 Atom – smallest piece of matter that still retains the
property of the element
 Atoms are composed of…
 Protons
 Neutrons
 electrons
Inside the Nucleus
 Atoms contain a center positively charged that is
composed of neutrons and protons
 Protons – particles with an electrical charge of +1
 Neutrons – neutral particles that do not have an electrical
charge
Outside the Nucleus
 Outside the nucleus is a cloud of particles called
electrons
 Electrons – particles with an electrical charge of -1
Atoms
 Atoms of different elements differ in the number of
protons they contain
(They usually differ in electrons and neutrons as well)
Electron Cloud
 Many models for the atom have been attempted, but by
1926 scientist developed the electron cloud model that
we use today.
 Electron cloud – is the area around the nucleus of an
atom where its electrons are most likely found
 This area is 100,000 times larger than the diameter of the
nucleus