Methane.
Water - H2O
Methane - CH4
Methane has 2 more hydrogens than water.
3.5 M has 3.5 moles per litre
so we have one litre, so we need 3.5 moles
moles = mass/molarmass
3.5 * 23 = 80.5
solution:
You need to find the frequency, and they have already given you the wavelength. And since you already know the speed of light, you can use formula (2) to answer this problem. Remember to convert the nano meters to meters because the speed of light is in meters. 

Answer:
IMPACTO AMBIENTAL EN LOS DISEÑOS Y CONSTRUCCIÓN
Explanation:
Los impactos directos por el uso de las vías terrestres pueden incluir: mayor demanda de combustibles para los motores; accidentes con los medios no motorizados de transporte o el reemplazo de los mismos; mayor contaminación del aire, ruido, desechos a los lados del camino; daños físicos o muerte a animales y personas ...
Nonrenewable<span> energy </span>resources, like coal, nuclear, oil, and natural gas, are available in limited supplies. This is usually due to the long time it takes for them to be replenished.Renewable resources<span> are replenished naturally and over relatively short periods of time</span>