Complete the indicated task to unlock the achievement.

Achievement	How to unlock
Brownian Motion	Pass the toilet paper to the scientist in need.
Caffeine Extraction	Perform surgical caffeine extraction from 20 machines.
Calculated Trajectory	Kill 10 Airborne Headcrabs using the Shotgun.
Centripetal Attraction	Kill 20 enemies with the Hivehand.
Convection Refinement	Ruin the microwave casserole.
Dead Reckoning	Kill an Assassin with the .357 Magnum.
Digital Wizardry	Kill 10 enemies with a reprogrammed Sentry.
Ethically Questionable	Conduct all of the questionable research experiments.
Futile Resistance	Kill 10 enemies with Snarks.
Gray Matter Propulsion	Headshot 20 enemies with the .357 magnum.
Hyper Saturation Conundrum	Drown in Lambda Core's coolant.
Inflammatory Actions	Kill a Headcrab using fire.
Kinetic Repulsion	Kill a Marine with their own grenade.
Mega Hertz	Kill 5 enemies with one grenade.
Nuclear Fishin'	Kill an Icthyosaur with either the Tau or Gluon.
Permeable Infrastructure	Use the alternate path in Office Complex.
Premature Expulsion	Use an entire clip of Gluon ammo in one continuous shot.
Prophylactic Suggested	Get overtaken by a Headcrab's ample anterior.
Proverbial Tinkerer	Interfere with the alarm and laptop in Anomalous Materials.
Quantum Capacitance	Overcharge it anyway.
Rare Specimen	Send the Hidden Hat to Xen.
Remote Detonation	Kill a Barnacle with a Satchel.
Resonance Procrastinator	Refuse to insert the specimen into the Anti-Mass Spectrometer.
Unified Coupling Theorum	Help the Barnacle and Headcrab find true love.
Universal Gravitation	Get killed by your own Snarks.