Which trends is indirectly proportional to effective nuclear charge

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.

What are known as the properties of substances that describe a substance et does not change that substances?

If you divide a speed in miles per minute by 60, you get the same speed expressed in miles