One example is a coral reef.
Answer:
covalent bond
it has 1 (outer most shell)
it has 7 (outter most shell)
hydrogen gains 1 chlorine gains 1
Explanation:
covalent bond as atoms share electrons to achieve full outer shell if electrons
hydrogen gains one to achieve 2 electrons in outer shell
chlorine gains 1 to achieve 8 electrons in outer shell
tundra and tropical rain forest
