Is it true that radioactive elements decay over time into other elements?

Question

Please explain this. so does this prove that the universe had a beginning? i mean, if radioactive uranium eventually turns into lead, and if all uranium atoms were infinitely old, they would all be lead by now, but they're not. so to me that proves that the universe is not infinetly old, and had to have a beginning.

Answer 1

Yes, that is correct: radioactive elements decay over time into other elements. Here is how that works.

The nuclei of atoms consist of protons and neutrons, held together by the strong nuclear force. However, protons are positively charged and the nucleus would fly apart, without the extra "glue" provided by the neutrons.

There is an ideal ratio between protons and neutrons. In light elements, like Carbon and Oxygen, this ideal ratio is 1:1. In heavy elements more neutrons are needed. In Uranium it's about 1.6:1 .

If there are too many or too little neutrons the nucleus tries to stabilize itself, by changing a neutron into a proton, or vice versa, whatever is needed, or to release a double pair of protons and neutrons. Often, like in Uranium, one transformation is not enough and one needs a whole decay chain.

Uranium-238 is a strange case: it's *almost* stable and it takes 4.5 billion years before half of a pile of U-238 atoms has disintegrated. That is such a long time, that there is still a lot of Uranium left since its formation in a supernova. After all, the Universe is only 13.5 billion years old!

Answer 2

Those very heavy elements like uranium were created from supernovae, which was long after the big bang. So the one wrong statement you work with is that uranium atoms are infinitely old. They are not. But, to your original question, the answer is yes, radioactive elements, for the most part, decay into other elements.

Answer 3

Yes, they do. The reason there's still uranium on the planet is because it decays very slowly. Some radioactive elements with a shorted decay time than uranium may have existed on earth but isn't any more because the have turned to other elements.

Answer 4

yes they do. because radio active elements are un stable and they continuously emit their fundamental particles to form other elements.