Warm-Up #22 A. 34 Copy and Answer
1. How many valence electrons does calcium
have?
2. If calcium lost two electrons, what would be
its charge?
3. How many valence electrons does sulfur
have?
4. If sulfur gained two electrons, what charge
would it have?
5. How could you represent the valence
electrons on an atom with just using the
chemical symbol?
Warm-Up #23 A.36 Copy and Answer
Many stores have a small container of
pennies near the cash registers. Many
people leave a penny or two in it when
they receive change. Others take a
penny or two when they need to. How
is this similar to ionic bonding?
Warm-Up #23 A. 36 Copy and Answer
1.
2.
3.
4.
How many protons are in Nitrogen?
How many neutrons are in Nitrogen?
How many electrons are in Nitrogen?
Draw a model of Nitrogen using energy
levels.
5. How many valence electrons does
Nitrogen have?
Warm-Up #24 A.37 Copy and Answer
1. How many protons are in Sodium?
2. How many valence electrons are in Boron?
Matching
3. In an ionic bond, _____ lose electrons.
4. In an ionic bond, _____ gain electrons.
5. A(n) _____ is an atom that loses electrons and becomes
positively charged.
6. A(n) _____ is an atom that gains electrons and becomes
negatively charged.
a. cation
b. metal
c. nonmetal
d. anion
Ionic Bonding
Ionic Bonds
• What are ionic bonds?
–An ionic bond forms when valence
electrons are transferred from one
atom to another atom.
Ionic bonds are all around us.
Salt – Sodium Chloride
Snail’s Shell – Calcium Carbonate
How are ionic bonds formed?
• In an ionic bond, one atom has lost
electrons and the other atom has gained
electrons.
• These atoms are called ions.
• An atom that loses electrons becomes
positively charged (cation)
• An atom that gains electrons becomes
negatively charge (anion)
Another Viewpoint
+
Can more than one electron transfer?
• YES!!!!
• Elements in Group 2 will donate 2
electrons and be given a +2 charge.
– Magnesium will react with Oxygen to form
Magnesium Oxide (MgO)
A Few Rules for Ionic Bonds
• Ionic bonds form between a metal and a
nonmetal.
• Metals lose the electrons becoming the
cation.
• Nonmetals gain electrons and become the
anion.
• The resulting ionic compound is
electrically neutral because the charges
between the atoms cancel.
Ionic Compounds
• Ionic compounds are made up of ions that are
bonded in a repeating three-dimensional pattern
called a crystal lattice.
Two Dimensional View
3-D View
Properties of Ionic Compounds
• Brittle solids at room temperature
• High melting points
– MgO has a melting point of 2800 degree C
• Very high boiling points
• High solubility in water (dissolve easily in
water)
Vocabulary Review
• Ion: a charged particle that forms when atoms
gain or lose electrons
• Ionic bond: the attractive force between
oppositely charged ions, which form when
electrons are transferred from one atom to
another
• Cation: positively charged ion
• Anion: negatively charged ion
• Crystal lattice: the regular pattern in which a
crystal is arranged