The area is called the anterior fontanel and closes anytime between 9 and 18 months of age.
Answer: radiation i think
“Diffusion sees molecules in an area of high concentration move to areas with a lower concentration, while osmosis refers to the process by which water, or other solvents, moves through a semipermeable membrane, leaving other bits of matter in its wake.”
Reference: sciencing.com
Hope this helps! :)