Explanation:
It is known that like charges repel each other and unlike charges attract each other.
As the balloons are facing each other with like charges so they will repel each other. Hence, they will move apart.
But when balloons were moved further apart then interaction between them will decrease and then there will be no force of repulsion or force of attraction.
Answer is: lithium is the least reactive and potassium is the most reactive of the three alkali elements.
<span>The </span>reactivity<span> of the alkali metals increases down the group because one valence electron (I group of Periodic system of elements) is farther away from nucleus and attraction force between electron and proton is weaker.</span>
A homogenous mixture is uniform and thus hard to recognize as a mixture. An example is water!
