Ch+2+-+Lesson+2+Organizer
30 Understanding the Atom
Copyright © McGraw-Hill Education.
Protons, Neutrons, and Electrons—How Atoms DifferLesson 2
Skim Lesson 2 in your book. Read the headings and look at the photos and illustrations.
Identify three things you want to learn more about as you read the lesson. Record your ideas
in your Science Journal.
Distinguish parts of the atom.
Part Electron Proton Neutron
Symbol
Charge
Location
Relative
Mass
Relate details about atomic number.
Atomic Number
determines equals ,
and also equals
in neutral atoms
Differentiate numbers of protons and neutrons in different isotopes
of the same element.
Numbers of
protons:
Numbers of
neutrons:Isotopes of
the Same
Element
Contrast the numbers of particles represented by an element’s mass
number and atomic number.
Atomic Number Mass Number
The Parts of the Atom
I found this on page
.
Neutrons and Isotopes
I found this on page
.
Different Elements—
Different Numbers of
Protons
I found this on page
.
I found this on page
.
1
Rt IElectron cloud nucleus. Nucleus
1/1,840. 1
The type of
elements
The number of protons
The number of electrons
Always have the
same number
Are going
to change
Some protons Some neutrons
Understanding the Atom 31
Lesson 2 | Protons, Neutrons, and Electrons—How Atoms Differ (continued)
Copyright © McGraw-Hill Education.
Define average atomic mass.
Differentiate three types of nuclear decay that occur in
radioactive elements.
Type Change Result
Alpha
decay
Beta decay
Gamma
decay
Contrast the formation of ions.
Positive Ion Negative Ion
A neutral atom
.
Result:
.
A neutral atom
.
Result:
.
Summarize why people were unsuccessful over 1,000 years ago when they
tried to transform lead into gold. What process would they have needed to complete in order to
have been successful?
I found this on page
.
Radioactivity
I found this on page
.
Ions—Gaining or Losing
Electrons
I found this on page
.
The average mass of an elements isotopes,
weighted according to the abundance of each
isotope
Two protons and
neutrons
New elements
atomic number
decreased by two
Neutrons becomes
a proton
New elements
atomic number
increase by one
Release of the
gamma rays Same elements
no change in the
protons
Loses one or more
Electrons
The atom has a
positive charge
Gains one or more
Electrons
The negative
becomes a positive
They did not have the technology to make this change