Download Distinguish Between Atoms

Distinguish Between Atoms
Chapter 5 Section 3
• The
structure
of the
atom
• Amu =
atomic
mass unit
• The atom has three subatomic
particles
– The protons (+ charge) and 1 amu
– The neutrons (0 charge) and 1 amu
– The electrons (- charge) and 0 amu
• The protons and the neutrons are
located in the center (nucleus) of the
atom.
• The electrons are moving around the
nucleus.
• All of the mass of the atom is located
in the nucleus.
The Atomic Model of the Helium Atom
2P+
2N
e-
e2 electrons
Subatomic Particles
Subparticle Charge Location Mass
in the
(amu)
atom
Electrons
negative Around
(-)
nucleus
0 amu
Protons
Positive Nucleus
(+)
1 amu
Neutrons
neutral
(0)
1 amu
Nucleus
Identifying Atoms
• The
• The atoms in the periodic
Atoms
table have a neutral charge.
in the
– Number of protons (+) =
periodic
number of electrons (-)
table
• An oxygen atom has 8 protons
(+8) and 8 electrons (-8)
(+ 8) + (-8) = 0
• Atomic
Number
of an
element.
• It is the number of protons in the
nucleus.
– Atomic number = Number of protons
11
Na
22.99
• It is the number on top of the
chemical symbol in the periodic
table.
• Why atoms
of one
element are
different
from atoms
of another
element?
• Atomic
number = ID
of an
element
• Atoms are different because
they contain different number
of protons (different atomic
number).
– All oxygen atoms have 8
protons in the nucleus.
– All hydrogen atoms have 1
proton in the nucleus.
• The periodic table is organized
by increasing atomic number.
• The nucleus
of the atom
has protons
and
neutrons.
• Mass number is the number of
protons and neutrons in an atom.
• Mass number is the rounded
number under the chemical
symbol.
• How to find
the number
of neutrons
of an atom
• Mass number = Number of protons +
Number of neutrons
• Number neutrons = Mass number
- Atomic number
Atomic Number and Mass Number
Atomic Number
Symbol
11
Number of protons
Na
23
MASS NUMBER
Sodium
Possible Test Question (PTQ)
30
Zn
65.39
• How many protons does
Zn have?
• Assuming that the Zn
atom is neutral, how
many electrons does it
have?
• How many neutrons
does Zn have if the mass
number is 65?