CHAPTER 19
“Properties of Atoms & the Periodic Table”
Section 1 – Structure of the Atom
I. Scientific ____________
A) Chemical ____________ - an abbreviated way to write the name of an element.
1) Examples:
 Iron
=
_____
 Mercury
=
_____
 Chlorine
=
_____
 Gold
=
_____
II. Atomic Components
A) ____________ - the smallest piece of matter that retains the property of the element.
1) Parts of the atom:
a) ____________
 Positively-charged center
 Contains most of the mass of the atom
b) ____________ (p+)
 Positively-charged particle
 Located inside of the nucleus
 The mass of a proton is 1 amu (atomic mass unit)
c) ____________ (no)
 Neutrally-charged particle
 Also located inside the nucleus
 The mass of a neutron is about 1 amu (atomic mass unit)
d) ____________ (e-)
 Negatively-charged particle
 Located inside the electron cloud which immediately surrounds the
nucleus (the electron orbits around the nucleus)
 The mass of an electron is about 1/2000 that of a proton (or 0 amu)
e) Electron ____________
 The area around the nucleus of an atom where its electrons are most
likely to be found.
 It is 100,000 times larger than the diameter of the nucleus
2) Energy ____________ & Electrons:
a) Due to the small mass of the electron, its exact ____________ is impossible to
determine.
b) We can only describe its ____________ location.
c) Electron clouds are divided into ____________ levels
 Each energy level can only hold a certain number of ____________
 Maximum number of electrons = 2(n2) …n represents the energy level
o 1st energy level =
_____ electrons
nd
o 2 energy level =
_____ electrons
o 3rd energy level =
_____ electrons
(*See page 592)
III. ____________: Even Smaller Particles
A) Quarks - particles of matter that makeup protons and neutrons
1) Six (6) different types of quarks
a) Three (3) makeup the ____________ and three (3) makeup the ____________.
2) Finding quarks…
a) ____________ - a machine designed to generate enough energy to study quarks
 Located in Batavia, IL (The Fermi National Accelerator Laboratory)
 The machine is also known as a ____________
IV. Models—Tools for Scientists (timeline of contributions leading to the discovery of the atom)
 Greeks  ____________ - matter could not be divided continuously (“atomos”)
 1800’s  ____________ - all elements are composed of atoms…
 1897  ____________ - atoms are made of smaller particles (discovered ____________)
 1911  ____________ - atoms are mostly empty space with the electrons floating around
the nucleus
 1913  ____________ - electrons move in definite paths at certain distances from the
nucleus
 REFER to the National Geographic section entitled, “Visualizing the Atomic Model” (p.582)
Section 2 – Masses of Atoms
I. Atomic ____________
A) Atomic ____________
 The number of protons (p+) in an atom
 Protons identify an ____________
B) Mass ____________
 The sum of the number of protons and the number of neutrons in the nucleus of an
atom
 Mass number = # of protons + # of neutrons
 Therefore, # of neutrons = mass number – atomic number
II. ____________ - atoms of the same element that have different numbers of neutrons
A) Isotopes have different mass numbers
B) Examples 
 Carbon 12 and Carbon 14
 Boron 10 and Boron 11
C) ____________ atomic mass – the weighted-average mass of the mixture of its isotopes
(See the example on page 587 and also in Figure 7)
A.
How to find Protons
The number of Protons always = _______________________
B.
How to find Electrons
The number of Electrons in a neutral atom = _________________ and _________________.
C.
How to find Neutrons
Atomic mass number
- Atomic number
#######
= neutrons
D.
Isotopes
Background Information: Hydrogen has three isotopes: Hydrogen 1 known as protium; hydrogen 2 known as
deuterium; and hydrogen 3 called tritium. All have an atomic number of 1. Their masses are different.
Instruction: Using the information about each of the hydrogen isotopes, finish the table.
Name
Protium
Deuterium
Tritium
Atomic Number
1
1
1
Atomic Mass
1
2
3
# of protons
# of Neutrons
# of electrons
I Can Checklist
Chapter 19 Properties of the Elements
Sections 1 and 2
Section 1 Structure of the Atom



I can list the names and symbols of common elements
I can locate and label the parts of an ATOM including:

PROTON

NEUTRON

ELECTRON

QUARK

ELECTRON CLOUD
I can list the characteristics of
 PROTON
 NEUTRON
 ELECTRON
Section 2 Masses of Atoms





I can determine ATOMIC MASS
I can explain how protons and neutrons combine to give the atom mass.
I can determine ATOMIC NUMBER
I can explain why the atomic number is unique for each element
I can determine the number of
 Protons found in the atom
 Neutrons found in the atom
 Electrons found in the atom

I can explain what an ISOTOPE of an element is

I can write an isotope of an element.

I can determine if an atom is an isotope or a different element

I can predict how the addition or deletion of neutrons changes the atomic mass of
element.
an
“I have learned more from my mistakes than from my successes.”
Sir Humphrey Davy
(Discoverer of the elements Sodium, Potassium and Calcium)