Atoms that are unstable undergo radioactive decay,
Elements with half life(that's how we know that it decayed),
Atoms that release energy and particles(like alpha beta and gamma particles) and,
Elements that have turned into a new element (as in radioactive decay no. of protons can decrease)
And to be precise the elements that have neutron to proton ratio of more than 1 undergo radioactive decay, since the nuclear attraction gets all weird after that.
The relation between the tiger and the goldfish is that they are both animals that fall into the category of vertebrates. This means that both creatures have spines, and internal bone structure. This is a trait that distinguishes them from the invertebrates that have no spine and bone structure, like the octopus for example, or from the creatures that have an exoskeleton, which means they have a bone structure that is covering the body, but not inside the body itself, like the scorpions for example.
Fungi I hope this helps haha
Answer:
1. Earth's ozone layer is responsible for absorbing infrared and ultraviolet rays from the sun.
2. Changes in the composition of the atmosphere have caused gradual changes in earth's climate, causing changes in plant and animal life that contributed to mass extinctions.
3. Chemical chlorofluorocarbons (CFCs) have been banned and replaced with hydrochlorofluorocarbons (HCFCs).
4. Naturally occurring volcanic eruptions can produce large amounts of gases which contain sulfur. These gases accumulate in the atmosphere in the same way as man-made sulphuroxides.
Sorry, but after that I don't know.
Explanation: