Can the bonds of atoms in materials break and reform when an energy is exposed to them? For instance you have a cup of liquid made up of iron atoms. If you hold a certain type of energy near it, it turns into a solid block of iron. When you pull hte power source away, it turns back into a liquid. I am also looking for websites to learn more.

The process you're talking about is just melting, which by definition means that the substance has to be able to return to its initial state. One thing I would say, however, is that the process of a liquid turning into a solid would release energy rather than requiring it.

It's the opposite of melting, really, if it turns liquid when you remove the heat source. But as hypervalent_iodine says, the process of solidification releases energy, so what you describe isn't going to happen.

There are some plastic materials with strange properties like you describe; viscoelasticity.

 

If you have ever played with silly putty, if you gently pull it, the silly putty stretches like a viscous liquid. But if we add energy quickly, such as quick pull, it acts like a solid. If you throw it against a wall or the floor it bounces like a super ball.

 

 

Silly Putty's unusual flow characteristics are due to the ingredient polydimethylsiloxane (PDMS), a viscoelastic substance. Viscoelasticity is a type of non-Newtonian flow, characterizing material that acts as a viscous liquid over a long time period but as an elastic solid over a short time period.

The properties of silly putty is time dependent. If we add the energy, slowly, over a long time the silly putty acts like a liquid. But if we add the same energy, but over a short time; bounce, it acts like a solid.

In this case, the bonds between the silly putty molecules are weak secondary bonding. If we go slow these weaker bond will slide past each other. If we go fast, there is not enough time for them to slide and the entire material acts like it is solid.

 

Research duo discover why non-Newtonian fluids harden on impact http://www.phys.org/news/2012-07-duo-non-newtonian-fluids-harden-impact.html