. Show all of your work. A radioactive cloud may contain Iodine-131, which has a half-life of 8 days. If the waste must decay to a concentration of less than 0.1% to be considered safe, it will take approximately days to reach safe levels.

4 days

Explanation:

A radioactive cloud is said Ron contain Iodine-131. It has a half-life of 8 days. If the waste must decay to a concentration of less than 0.1% to be considered safe, then it will take approximately 4 days days to reach safe levels under normal circumstances.

sodium (na), for example, has one electron in its valence shell. this is an unstable state because that valence shell needs eight electrons to be full. in order to fill its valence shell, find a way to add seven electrons to its valence shell

true

hope that