Which statement best describes the properties of ionic compounds? A. They are brittle, solid at room temperature, and have a high melting point. B. They are always composed of an equal proportion of cations to anions. C. They mostly have low melting and boiling points. D. They are good conductors of heat and electricity and are ductile and malleable.

Anne applies a force on a toy car and makes it move forward. what can be said about the forces acting on the toy car at the moment anne applies the force?

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?

How have the competing explanations' experiments on atoms affected the development of the atomic model?