Electronegativity, intermolecular forces, and water Flashcards
By the end, you must be able to explain the concept of electronegativity, and how it influences biological molecules
What is a Covalent bond
when atoms share one or more pairs of valence electrons
What happens when the EN is high
the element has a high tendency to attract the electrons in a covalent bond
What happens if an element with a high EN is in a covalent bond
the element develops a slight negative charge
What happens when the EN is low
the element has a low tendency to attract a bond
What happens if an element with a low EN is in a covalent bond
The element develops a slight positive charge
What are the molecules with a + and - charge called
polar molecules
How can intermolecular force form
between molecules (van der Waals forces)
What is the London Force
The weakest out of all three forces
What is the Dipole-Dipole forces
Formed between the + and - sides of polar molecules
What are hydrogen bonds
- a very strong dipole-dipole force
- form between H atoms and neighboring N, O or F atoms
- very important biologically
What type of molecule is water
a polar molecule
How will water form hydrogen bonds
- with other water molecules (cohesion)
- with other polar molecules (adhesion)
What do waters high specific heat capacity result in
- hydrogen bonds
- absorb a lot of heat energy with minimal temperature change
- a lot of energy is needed to convert water from liquid to a gas
Why does ice float
fewer or slower formations of hydrogen bonds
Why is water important
temperature regulation, moisture, lubrication, chemical reaction
