Plasma membrane is the answer
Because matter cannot be created or destroyed
Explanation:
the lone pairs will be negatively charged. these have a repulsion effect on other negatively charged electrons in the shells of atoms. picture a water molecule: the lone electron pair on the top of the oxygen will have a repulsion force on the 2 hydrogen atom's orbiting electrons to cause a bent molecular geometry.
In a solid the particles are all really close together and stuck like that. As the solid melts and becomes a liquid the particles spread out. A solid won’t easily change its shape because the particles are bound together but in a liquid the shape is more fluid, take water when you pour it into a container it will change to fit the shape of a container this is because the particles aren’t as close and can move around. The particles of a solid change when it melts because it is changing states to a liquid.