Nitrogen can ionically bond with an unknown element x from group 2. how many ions of element x are required to create a stable ionic compound with nitrogen? a) 2 b) 3 c) 4 d) there is not enough information.

Starting with only the balmer series light (visible light), how could we ensure that the solar panels generate a current that mark can use for his power station? a)by gradually increasing the brightness (amount) of light that we shine on it. b)by gradually increasing the frequency of the light we shine on it. c)by gradually increasing the wavelength of the light that we shine on it.