Melting ice cream is a physical change because it is a phase change, the water in the ice cream gains thermal energy and the inter-molecular forces are overcome and the molecules move further apart forming a liquid. It is not a chemical change because no chemical reactions occurred.
C. CaCl2 is the correct answer
A factor that is changed in an experiment is called the Independent Variable.
Explanation:
1.undetectable to electromagnetic waves
2.hiding an object from an illumination containing diffre t wave lengths become difficult as the object sizes grow.
3. reduce the scattering by two orders.