Because there are so many different values of numbers, it would be impractical to use 1Ω, 2Ω, 3Ω... etc... Using colored bands helps make reading it a little easier to the trained eye. There are hundreds of thousands, if not tens of millions of different resistors would need to exist to cover every value. So you just use something called "preferred values" with their resistance values posted on them instead.
Here is what radioactive decay is:
<span>Radioactive decay is the spontaneous breakdown
of an atomic nucleus resulting in the release of energy and matter from
the nucleus. Remember that a radioisotope has unstable nuclei that does
not have enough binding energy to hold the nucleus together.</span>
Answer:
Aluminum , iron , gold , silver , nickels etc are the type of elements form metallic bonds .
Chemical change because it cannot be reversed