To show up somewhere you're not expected is to show up this way
Unannounced
A type of graph representing percentages as sections of a circle, it'd be weird to get one à la mode
Pie-Chart
A malt beverage, or to be unwell
Ale/Ail
Highway to Hell, Back in Black, Who made Who
AC/DC
Covalent bonds share valence these
It's a 500-year anniversary
a quincentennial
These tasty-sounding bits of info stored on a computer can help maintain a user's browser session
Cookies
Summoned up courage, or a hot dog condiment
Mustered/Mustard
Gaucho, Katy Lied, Can't Buy a Thrill
Steely Dan
These units of heat weigh in at just over 4 joules; the ones counted by dieters are actually "kilo-" sized
calorie
Adjective describing a game in the NCAA when a team from the Pac-12 plays a team from the Big Ten
non-conference
This bakery term was used as slang for American soldiers during WWI
Doughboys
A part of the foot, or what you hope an injured foot would do
Heel/Heal
Moving Pictures, A Farewell to Kings, Permanent Waves
Rush
As the name implies, redox is a reaction in which these 2 actions take place
Reduction and Oxidation
Someone between 90 & 100 years of age
The event where Mary found out the Holy Spirit was going to help her conceive
This former name of the Hawaiian Islands sounds glutenous, but fret not
An adhesive, or to walk back and forth
Paste/Paced
All Eyez On Me, Me Against the World, Better Dayz
Tupac
Europium is one of these metals, though they're not as scarce as their name implies
Rare Earth Metals
The event where Mary found out the Holy Spirit was going to help her conceive
the Annunciation
This flawed logic is named for its twisted nature & numerous holes
Pretzel Logic
A plundered bounty, or a mideval string instrument
Loot/Lute
Disintegration, Three Imaginary Boys, Seventeen Seconds
The Cure
Though it doesn't start with that letter, "S" represents this measure of the molecular disorder in a closed system
Entropy