The answer would be "Gas".
Answer:Uranium
80 years
To make that nuclear reaction that makes that heat, those uranium pellets are the fuel. And just like any fuel, it gets used up eventually. Your 12-foot-long fuel rod full of those uranium pellet, lasts about six years in a reactor, until the fission process uses that uranium fuel up.
Transuranic wastes, sometimes called TRU, account for most of the radioactive hazard remaining in high-level waste after 1,000 years. Radioactive isotopes eventually decay, or disintegrate, to harmless materials. Some isotopes decay in hours or even minutes, but others decay very slowly.
Explanation:
Hope this helps
Calcium with water:
When a metal reacts with water( cold water or hot water) then the products formed are metal hydroxide and hydrogen gas.
Metal + steam --------> Metal hydroxide + Hydrogen
Calcium reacts with cold water to form calcium hydroxide and hydrogen gas:
potassium with water.
Potassium reacts violently with cold water to form potassium hydroxide and hydrogen gas:
2K(s)+ 2H2O(l) --------> 2KOH(aq) + H2(g) + heat.
In this reaction so much heat is produced get hydrogen gas formed catches fire and burns explosively.
The answer is D. A compound
A chemical compound can be described as substance composed of atoms from more than one element held together by chemical bonds in a fixed stoichiometric proportion. A compound has different physical and chemical properties from its constituent elements.
For example : compound water is made up of H and O bonded together and it has different properties from O and H.
Thus, among the given options, the one coreectly describing a compound is
a) The atoms are bonded together, and the compound has different physical and chemical properties than the individual elements.