Today’s Catalyst
1. What is a similarity between a compound and a
homogeneous mixture?
Uniform
Composition
2. What is a difference between a compound and
a homogeneous mixture?
A compound is two elements
chemically combined; a mixture is
two substances physically combined
Today’s Catalyst
3. How can a compound be separated? How can
a homogeneous mixture be separated?
Compound chemically separated
Mixture  physically separated
Today’s Catalyst
4. In J.J. Thomson’s
plum pudding model,
Thomson compared
raisins to what subatomic particle?
5. Draw a picture of J.J.
Thomson’s plum
pudding model. Why is
Thomson’s model
incorrect?
By the end of the class
period I will be able to…
Understand the
difference between
ions and isotopes
All atoms of the same element
have the same number of
PROTONS
Isotopes: atoms with the same
atomic number (number of
protons), but different number of
neutrons
When some types of
compounds are formed atoms
may gain or lose electrons
When some types of
compounds are formed atoms
may gain or lose electrons
ION: an atom that has gained or
lost one or more electrons
**atoms with the same atomic
number (number of protons), but
different number of electrons
QUICK SUMMARY TIME!
What is the difference
between ions and
isotopes? What is one
similarity?
Difference: Ions deal in changing
ELECTRONS; Isotopes deals in
changing NEUTRONS
Similarity: PROTONS ALWAYS REMAIN
THE SAME!!!!
CATION
An atom that has lost one or
more electrons (has an overall
positive charge)
Naming Rule:
element ion
A Sodium atom losing an electron
19
11
Na
11 Protons
8 Neutrons
A Sodium atom losing an electron
19
11
Na
11 Protons
8 Neutrons
A Sodium atom losing an electron
19
11
Na
11 Protons
8 Neutrons
A Sodium atom losing an electron
19
11
Na
+1
11 Protons
8 Neutrons
Na
+1
A Sodium atom losing an electron
19
11
Na
+1
11 Protons
8 Neutrons
Na
+1
Sodium Ion
Quick Check!
If a neutral Magnesium atom loses two
electrons, what will its overall charge be?
A. -2
B. +1
C. +2
D. -1
C
Quick Check!
How many electrons are in an ion of K+1?
A. 39
B. 18
C. 19
D. 20
B
ANION
An atom that has gained one
or more electrons (has an
overall negative charge).
Naming Rule:
root + “ide” ion
An atom gaining an electron
17
9
F
9 Protons
8 Neutrons
An atom gaining an electron
17
9
F
9 Protons
8 Neutrons
An atom gaining an electron
17
9
F
9 Protons
8 Neutrons
An atom gaining an electron
17
9
F
9 Protons
8 Neutrons
An atom gaining an electron
17
9
F
-1
9 Protons
8 Neutrons
F
-1
An atom gaining an electron
17
9
F
-1
9 Protons
8 Neutrons
F
-1
Fluoride Ion
Quick Check!
If a neutral oxygen atom gains two
electrons, what will its overall charge be?
A. -2
B. +1
C. +2
D. -1
A
Quick Check!
How many electrons are in an ion of Br -1?
A. 35
B. 34
C. 36
D. 79
C
Trends on Periodic Table
+1
+2
+3
-2 -1
IONS
CATIONS
Typically formed by
metals.
ANIONS
Typically formed by
nonmetals.
Naming Rule:
Naming Rule:
element ion
root + “ide” ion
Ionic compounds form from a
combination of positive and negative
ions. The resulting compound is
electrically neutral.
Predict the formula of the compound
formed from the following pair of ions…
+1
Na
and
NaCl
-1
Cl
Today’s Homework
• Worksheet (2
sided)