An element in group iia would form a ion while an element in group viia would form a(n) ion. a. negative, positive b. positive, negative c. positive, uncharged d. negative, uncharged

Matter that emits no light at any wavelength is called

Ultraviolet radiation is dangerous because it has a high enough energy to damage skin cells. what is the best explanation of the relationship between wavelength and wave energy? a) wave energy is related only to frequency, not wavelength. b) longer wavelengths have lower frequencies but higher energy. c) the shorter the wavelength, the lower the frequency and the higher the energy. d) the shorter the wavelength, the higher the frequency and the higher the energy.

50 points to who answers this question in a clear and simple explanation : to what hight will a mass of weight of 500 n be raised in 20 seconds by a motor using 4kw of power?