I need help please, thanks!

Explain why you don't notice that objects around you have a wavelength.

This question is somehow not clear, because a typical human eye can notice objects which have wavelengths from about 380 to 740 nanometers. This is called visible spectrum (the portion of the electromagnetic spectrum that is visible to the human eye). Electromagnetic radiation in this range of wavelengths is called visible light or simply light.

Someone even can see extra colors - they able to see beyond the visible spectrum. The reason that the human eye can see the spectrum is because those specific wavelengths stimulate the retina in the human eye. The human retina can only detect incident light that falls in waves from about 380 to 740 nanometers long, so we can’t see microwave or ultraviolet wavelengths. This also applies to infrared lights which has wavelengths longer than visible and shorter than microwaves, thus being invisible to the human eye.

In conclusion, the human eye can not notice that objects with wavelength not in the range of 380 to 740 nanometers.

Explanation:

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

what is the question here. i think you messed up.