Answer:
the formula of its oxide is X2O3.
Potassium (K) is in Group I of the periodic table, and elements in the same column (period) are similar. Sodium (Na), or lithium (Li) are similar.
<span>The correct answer is b. Radon. Oxygen, Hyrdrogen, and Boron, are not radioactivel ike Radon and it regenerates quickly meaning that even though it has a short half-life period, it stays for a long time once released. It also has no taste so it's difficult to notice without proper gear because you can't feel it.</span>
A rapid release of stored up energy
