Radioactivity in our world <span>b. is as old as the universe.
</span><span>Radioactive atom spontaneously emits energetic particles or waves, while decays on lighter nuclei (atoms with smaller atomic mass). Radioactivity is used to calculate how old is Earth and living things, for that purpose isotope of carbon is used.</span>
It’s D,the cold will bring cooler temperatures.....:)
After that have been up for a while thay are metal
It is not important not to mix R-22 and R-401A refrigerants in the same container because:
d. they use different oil.
The Freon in both systems are essentially the same but the oils in each system are not compatible which will render the mixture of the two systems useless.