7th Grade Science
Atoms and Bonding
New
Element
Molecule
ION
Isotope
2
Answer these questions:
NEGATIVE
An atom that gains one or more electrons will have a ____________________
charge.
POSITIVE
An atom that loses one or more electrons will have a ____________________
charge.
ION
An atom that gains or loses one or more electrons is called an ____________.
CATION and a negative ion is called an
A positive ion is called a ______________
ANION
_______________.
“Cat-Eye-On”
“An-Eye-On”
Section A: Complete the chart using a periodic table to help you.
Cl
K
Mg
F
Al
Na
N
O
H
C
I
17
19
12
9
13
11
7
8
1
6
53
7
1
2
7
3
1
5
6
1
4
7
Gain 1 -1
Lose 1 +1
Lose 2 +2
Gain 1 -1
Lose 3 +3
Lose 1 +1
Gain 3 -3
Gain 2 -2
Gain/lose 1 +1 or -1
Gain/lose 4 +4 or -4
Gain 1 -1
- Ionic Bonds
Ions and Ionic Bonds
5
IONIC BONDING with
SODIUM AND CHLORINE
6
What is an ionic bond?
Atoms will transfer one or more ________________
ELECTRONS to another to form the bond.
COMPLETE outer shell.
Each atom is left with a ________________
An ionic bond forms between a ___________
METAL ion with a positive charge and a
________________
NONMETAL ion with a negative charge.
Example B1: Sodium + Chlorine
Example B2: Magnesium + Iodine
Example B3: Potassium + Iodine
Example B4: Sodium + Oxygen
Ex. B5: Magnesium + Chlorine
Ex. B6: Aluminum + Chlorine
- Ionic Bonds
Properties of Ionic Compounds
•Hard, brittle crystals – lattice structure
•Have high melting/boiling points
•When dissolved (soluble) in water or
melted, they conduct electricity.
9
What is a covalent bond?
Atoms ___________
SHARE one or more electrons with each other to form the bond.
COMPLETE outer shell.
Each atom is left with a ________________
NONMETAL
A covalent bond forms between two _________________.
Example C1: Hydrogen + Hydrogen
Example C2: 2 Hydrogen + Oxygen
Example C3: Chlorine + Chlorine
Example C4: Oxygen + Oxygen
Example C5: Carbon + 2 Oxygen
Example C6: Carbon + 4 Hydrogen
- Covalent Bonds
How Covalent Bonds Form
•The force that holds atoms together in a covalent
bond is the attraction of each atom’s nucleus for
the shared pair of electrons.
12
Properties of Molecular Compounds
(covalent compounds)
13
Ionic or Covalent Bonding Lab
I will look at your data
Conclusion Questions:
1) Properties of Covalent compounds
Low melting point
does not conduct electricity
soluble in water (this one has a high solubility)
2) Properties of Ionic Compounds
High melting point
conducts electricity
Soluble in water (this one has a low solubility)
3) Covalent compounds form with two or more nonmetals
4) Ionic compounds form with a metals and nonmetals.