What is the purpose of the zigzag line on the periodic table

Three point charges, two positive and one negative, each having a magnitude of 20 μc are placed at the vertices of an equilateral triangle (30 cm on a side). what is the magnitude of the electrostatic force on the negative charge

What type of light does this light bulb produce most (i.e. at what wavelength does the spectrum have maximum intensity)?

Acompound machine is also called a machine. a. force b. simple c. complex d. directional