(Ch. 10) Chemical Bonding Flashcards
(27 cards)
What is a Chemical Bond?
A strong attractive force between atoms in a compound.
What are the two types of chemical bonds?
- Ionic Bonds
- Covalent Bonds
What is an Ionic Bond? Give an example.
A bond formed by electrostatic attraction between positive and negative ions.
(ex. NaCl)
What is a Covalent Bond? Give an example.
A bond formed by the sharing of electrons between covalent/molecular compounds.
(ex. Hydrogen Bonds)
What is Electronegativity?
The ability of an atom in a molecule (covalent bond) to pull electrons towards itself.
What is the range of Electronegativity?
(.70- 4) ♥️
What is a Lewis Symbol?
The chemical symbol of an element with a dot for each VALENCE electron. (element name surrounded by dots)
What is a Lewis Structure?
A drawing that shows…
1. how valence electrons within a compound are distributed
AND
2. how atoms are connected to one another
How do you draw a Lewis Structure of a Ionic Compound?
- Draw the Lewis Symbol of both the metal and non-metal.
- Determine the charge that will be formed.
- Place the anion and it’s dots in brackets with charge as a subscript (but in the upper right hand corner of the bracket)
- Place the cation with it’s charge.
What is the Octet Rule?
Atoms tend to gain, lose, or share electrons until they are surrounded by eight valence electrons.
What is the first step of drawing a Lewis Structure of a Covalent Compound?
First, you add the total valence electrons.
- If you have a cation (+) remove an electron for each positive charge.
- If you have an anion (-) add an electron for each negative charge. (double check ♥️)
Ok, we have added up the valence electrons…
What is the next step in drawing a Lewis Structure for a Covalent Compound?
Next, you determine which atom is the central atom (which is the least electronegative) and attach the other atoms to it.
- Hydrogen will NEVER be a central electron.
Ok, we know we added up the valence electrons, determined the central atoms….
What is the next step in drawing a Lewis Structure for a Covalent Compound?
- Now, we complete the octets to the non-central atoms first than the central atom.
- Any remaining electrons should be placed on the central atom. ♥️
How do we write out the Lewis Structure of a Covalent Compound that contains a Polyatomic Ion?
We place the overall structure in brackets and include the charge in the upper right hand corner.
What are the three exceptions to the Octet Rule?
- (B) Boron, which is happy with 6 valence electrons.
- (Be) Beryllium, which is happy with 4 valence electrons.
- (H) Hydrogen, which is happy with 2 valence electrons.
What is a Resonance Structure?
These are Lewis Structures that have the same atoms bonded to each other, but the placement of electrons are different.
What is a Resonance Hybrid?
An average of the possible Resonance Structures. ❤
What are the five Molecular Shapes?
- Linear
- Trigonal Planar
- Tetrahedral
- Trigonal Pyramidal
- Bent
Describe the Molecular Shape: Linear
A straight light with 2 bonding groups. (180 degrees between atoms)
Describe the Molecular Shape: Trigonal Planar
A flat triangle with 3 bonding groups.
(120 degree difference between atoms)
Describe the Molecular Shape: Tetrahedral
A cross/pyramid with 4 bonding groups.
(109.5 degree difference between electrons)
Describe the Molecular Shape: Trigonal Pyramidal
A simple pyramid with 3 bonding groups and 1 lone pair.
(less than 109.5 degree difference between electrons)
Describe the Molecular Shape: Bent
A bent line with two lone pairs and two bonding groups.
(less than 109.5 degree difference between electrons_
What is the Valence Shell Electron Pair Electron Theory?
This theory states that the best arrangement of a given number of electron groups is the one that minimizes repulsion between them.
