To give blood you must: 1  Be in general good health.  Be at least 17 years old. (If you are 16 you can donate with a CBC consent form signed by your parent). There is no upper age limit as long as you have no health restrictions.
Specific radiative intensity. Specific (radiative) intensity is a quantity used in physics that describes electromagnetic radiation. It is a term used in much of the older scientific literature. The present-day SI term is spectral radiance, which can be expressed in base SI units as W mâ2 srâ1 Hzâ1.
So by level of light you probably mean light intensity which is something that can be measured. Light intensity is usually defined as the energy hitting an area over some time period. So in the case of a plant, a higher light intensity means more packets of light called âphotonsâ are hitting the leaves.