Environmental, agricultural, and natural ecosystems.
The answer would be AB+40.
Answer:
Active uptake (which I think you mean active transport) is important when the concentration gradient is against that of a certain substance, so it doesn't cross the membrane through diffusion or passive transport. It is sometimes necessary if a substance needs to move across a membrane but can't do so due to electrical charge or that there is a substance on the other side of the membrane preventing diffusion.
Explanation:
A Non-metal and a Metal react together to form an ionic bond
metals lose electrons to match the numbers of their nearest noble gas
