In describing Experiment 1, the passage states that a control solution was prepared with no NaCl. Write a paragraph explaining the purpose of a control in an experiment and why this solution functioned as the control for the experiment described in the passage.

Which material produces static charge when rubbed?

When fat comes in contact with sodium hydroxide, it produces soap and glycerin. determine whether this is a physical change or a chemical change. explain your answer

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?