Ch 11/12 Flashcards
Valence electrons
Electrons involved in chemical bonds
What is a Chemical bond
The force of attraction that holds atoms or ions together in a chemical substance
Ionic
Metal and nonmetal
Formed when Electrons are transferred due to differences in electronegativity and ionization energy
Commonly called salts
Electro negativity of ionic bonds
1.7-4
Covalent bonds
Non metal and non metal
Electrons are shared equally
Commonly called molecules
Electronegativity of non polar covalent
0-.4
Electro negativity of polar covalent bonds
.4-1.7
Metallic. Bonds
Metal and metal
Sea of electrons
No electro negativity
Isoelectronic
When an atom gains or loses electrons to have the same number of electrons as the nearest noble gas
Most stable number of valence electrons
8 or an octet
Exception of He with 2
Electronegativity
A measure of how well an atom attracts electrons
How do metal atoms become Isoelectronic
They lose electrons
Becomes positive cation
How do non metals become Isoelectronic
They gain electrons
Becomes negative anion
Electrostatic attraction
The attraction between oppositely charged ions that makes atoms stick together in an ionic bond
Polyatomic ions
Groups of atoms that have an overall charge and act like a single ion
Common ion charges
Group 1- loses 1 Group 2- loses 2 Group 13- loses 3 Group 15- gains 3 Group 16- gains 2 Group 17- gains 1
Lattice energy
Measure of how much energy is released when bonds form
The more energy released, the stronger the bond
Ionic compounds
Form lattice crystals Brittle High melting points Soluble Form electrolytes
Pairs of bonds
One pair- single bond
2 pairs- double bond
3 pairs- triple bond
Non polar
When EN is less than .4 so neither electron can win so they share the atoms equally
Polar
When the EN is greater than .4 and one atom pulls the electrons closer to itself, making it partially negative and one atom becomes positive
How to tell which side is positive and which side is negative
The atom with the greater EN is the negative side of the molecule
4 effective pairs
Tetrahedral arrangement
3 effective pairs
Trigonal planar