Answer:
KBr, FeF3
Explanation:
Potassium ion (K+) + bromide ion (Br-) make the ionic compound KBr
Iron (III) ion (Fe3+) + 3 fluoride ions (F-) make the ionic compound FeF3
NH3 has covalent bonds so it isn't ionic
Mg12 is an elemental compound
I’m almost 100% sure it’s D
Explanation: Oxygen plays a very vital role in the life of aquatic animals. The dissolved oxygen in the water helps them to breathe under water.
Optimum level of oxygen for deep living animals like oysters, bottom feeders, crabs is around (1-6 mg/L), while the animals living on the upper side like fishes require a higher amount of around (4-6 mg/L).
If the oxygen concentration in the pond is not optimum, there will no aquatic life and hence, the ecosystem will be affected.
Hence, oxygen concentration affects the fishes that live in the pond to a higher extent.
HF because an element is always a capital then a lowercase letter
