Iron Man films Informatics Part 2: Arc Reactor and elements used to power it up

ARC REACTOR

Howard Stark and defected Soviet scientist Anton Vanko first designed the Arc Reactor. It was immense, Howard saw it as the stepping stone to create a new, stable element that would render nuclear power obsolete. But Anton saw it as a way to get rich and when Howard found out, he had Anton and his family deported. Howard's son, Tony, miniaturized the design and uses it to power the Iron Man armor.

After being critically wounded in an ambush by the Ten Rings, Tony Stark was imprisoned in a cave and ordered to build a missile for them, To save his life, fellow captive Dr. Yinsen put a electromagnet in his chest to keeps the shrapnel in Stark's chest from reaching his heart and killing him. The Ten Rings offers Tony his freedom in exchange for building a Jericho missile for the group, but Tony and Yinsen knew they will not keep their word. So Tony and Yinsen secretly build a device that provides a clean source of energy called an "Arc Reactor", to power Stark's electromagnet. A massive arc reactor provided power for the sprawling complex of Stark Industries. The arc reactor was allegedly capable of powering the electromagnet protecting Tony's heart for fifty lifetimes on its own and power a suit of armor to escape. 

PALLADIUM

Stark's design of the reactor in his chest required a heavy element such as palladium to keep it running. Unfortunately, palladium was continuously eroded by the neutron bombardment, and released deadly poisions into Tony's bloodstream. He grows increasingly despondent and reckless due to his impending death, and choosing not to tell anyone about his condition. As Tony came to understand that his demise was at hand, he began giving his possessions away, including appointing Pepper CEO of Stark Industries, and allowing Rhodey to 'steal' the Mark 2 Iron Man suit and take it back to the US Military. 

It wasn't until SHIELD's intervention that Tony's poisoning symptoms were temporarily reverted and he was set on the trail to find his father's design for a new element to replace the Palladium. Building a small particle accelerator in his garage, Tony was finally able to create a new element that met his needs, and in turn created a brand new suit to utilize the new power.

VIBRANIUM

Vibranium comes from a nation called Wakanda, a small country in Africa and is the rarest metal on earth. Vibraniun absorbs vibratory energy in its vicinity, such as sound waves, within itself. The apparent observable vibratory rate of the molecules of the Vibranium itself does not noticeably increase when the Vibranium absorbs mechanical energy. The outside vibratory energy is stored within the bonds between the molecules making up the Vibranium. 

Captain America's shield was constructed by Howard Stark using vibranium. Howard states that vibranium is stronger than and a third of the weight of steel, is completely vibration-absorbent. It was strong enough to resist several laser projections from the HYDRAs guns, powered by the Tesseract.

Tony Stark rediscovered the element after decoding a hidden message containing the structure of the element left in the diorama of the 1974 Stark Expo by his father, Howard. Although unnamed in the film itself, the novelization identifies the element as vibranium. Stark later uses it in an experiment and after charging it with a high power laser (and destroying most of the room) he uses it to prevent the poisoning of his blood.

Tony later uses new Arc reactor technology to develop a large scale version of the reactor to power his Stark Tower in New York City, which is said to have the ability keep the building running for over a year with clean energy. Tony's personal arc reactor prevents Loki from taking control of his mind, as the reactor blocks this effect of Loki's staff, which normally allows Loki to control the minds of others.