Answer:
substances can move from areas of low concentration to areas of high concentration
Explanation:
usually substances move across their concentration gradient which is from high concentration to low concentration. Active transport can allow substances to move against their concentration gradient.
answer:
The ionic bond is a bond between a metal and a non metal while a covalent bond is one between two non metals
Answer:
c I think because I remember this from a while ago
Environmental scientists are using GPS ( It is effective but expensive) aerial monitoring (Quick but not the easiest), RFID tags, (mostly for long-term monitoring) and hidden cameras are used to study polar bear behavior without interruption to their environment.