unit 7 test Flashcards
(15 cards)
What elements do ionic bonds form between?
metals and nonmetals
What is the electronegativity difference in Ionic bonds?
greater than 2.0 (usually)
True or false: Ionic bonds have a high melting/boiling point and can conduct electricity in a solution
true
What elements do covalent bonds form between?
nonmetals
What are some properties of covalent bonds?
low melting/boiling point, non-conductors of electricity, not water soluble
What is the electronegativity difference of non-polar covalent bonds?
less than 0.5
What is the electronegativity difference of polar covalent bonds?
greater than 0.5 and less than 2.0
How do polar covalent bonds effect the partial charges of atoms?
results in a charge separation in the bond; partial negative and partial positive
what are compounds formed by covalent bonds called?
molecules
Why do atoms form covalent bonds?
they want to achieve a full shell, but don’t want to give any electrons away, since they are already close to a full shell.
What are some properties of hydrogen bonds?
- high melting/boiling point
- ice less dense than water
- good solvent
- cohesion AND adhesion
- surface tension
What is one reason our bodies need water to survive?
Our kidneys need water to filter out bad stuff in our bodies.
What is a buffer?
A solution that resists changes in pH by absorbing excess hydrogen or donating hydrogen
What is pH?
The measure of the hydrogen ion concentration of a solution.
If a solution has a high hydrogen concentration, will it be an acid or a base?
It will have a low pH and be an acid.
