A because a primary source is defined as a first hand account of an event .
Is this science cuz if it’s is it’s A
Answer:
Potassium
Explanation:
In group one of the periodic table both the melting and the boiling points usually decrease down the group.
Now, down the group, it's lithium that comes first, then sodium, then potassium.
Thus, among the 3, potassium is furthermost down the group by virtue of the factor it has the highest atomic number.
Therefore, we can say that potassium has the lowest boiling point among the 3.
