Name ______________________
2.1 Notes: Atoms, Ions, & Molecules
Key Concept: All living things are based on atoms and their interactions.
Living things consist of different elements.
Atom: _________________________________________________________________________________
-Element: one type of atom
An atom has a nucleus and electrons.
-The nucleus has __________________ and ___________________.
- An energy level is an _______________________________________________________________.
Compounds
-A compound is made of _____________________________________________________________.
-Examples: _____________________________ & ______________________________
Ions form when atoms gain or lose electrons.
-Positive ions: formed when atoms __________________________________________
-Negative ions: formed when atoms __________________________________________
Ionic bonds form ________________________________________________________________________
Covalent bonds form when ________________________________________________________________
-Molecule: ________________________________________________________________________
2.2 Notes: Properties of Water
Key Concept: Water’s unique properties allow lift to exist on Earth.
Life depends on hydrogen bonds in water.
 Water is a ____________ molecule.
o Polar molecules: ______________________________________________________________
o Nonpolar molecules: __________________________________________________________
Hydrogen bonds are responsible for three important properties of water.
1. High specific heat: __________________________________________________________________
_________________________________________________________________________________
a. Example:
2. Cohesion: _________________________________________________________________________
a. Example:
3. Adhesion: _________________________________________________________________________
a. Example:
Many compounds dissolve in water.
 A solution is formed when ___________________________________________________________.
A solution is a _____________________________________________.
 Parts of a solution:
o Solvents ___________________________________________________________________
o Solutes _____________________________________________________________________
Polarity
 “Like dissolves like”
o Polar solvents dissolve polar solutes (Example: ______________________________________)
o Nonpolar solvents dissolve nonpolar solutes (Example: _______________________________)
o Polar substances and nonpolar substances generally remain separate (think of ______________)
Some compounds form acids or bases.
 Acids ____________________________________________________________________________
_________________________________________________________________________________
o pH: _____________________
 Neutral solutions ___________________________________________________________________
o pH: _____________________
 Bases ____________________________________________________________________________
_________________________________________________________________________________
o pH: _____________________