How can you provide more nucleation sites for crystal growth?

Question

What are nucleation sites, and how can you provide more of them in order to increase crystal growth?

I'm only a 9th grader in high school, so is there anyone who can explain this to me on simple chemistry/geology terms?

Answer 1

A nucleation site is a spot where a crystal can easily grow, allowing it to build up.

A common example of this is making rock candy. The sugar solution would take forever to crystallize left on its own, but when you put a string into it, it makes a nucleation site for the crystals to build up on.

Sometimes in chem lab when you are trying to get a crystal to form you can scratch the bottom of he beaker with a glass rod. This scratch gives the crystals something to "hold on" to.

http://en.wikipedia.org/wiki/Nucleation

Answer 2

Nucleation sites are imperfections in the base material where crystals start forming. If you have a perfectly smooth base material (also known sometimes as a substrate), nucleation will not occur. It's these microscopic imperfections that allows for growth. If you want a higher number (density) of crystals in the same amount of area, create nucleation sites by introducing imperfections. Scratching the substrate "unsmoothes" the surface.