Of the elements below, __________ has the highest melting point.
Rb
K
Li
Na
Cs
To find the element with the highest melting point among the given options, we need to refer to the periodic table. The melting point generally increases as you move across a period from left to right.
If we look at the given elements, we can see that they all belong to Group 1 of the periodic table, also known as the alkali metals. Alkali metals have low melting points compared to other elements because they consist of loosely held outermost electrons.
Among the given options, the element with the highest atomic number is Cs (Cesium). It is located at the end of the Group 1 elements. Cesium has the highest melting point of all the alkali metals due to its larger atomic size and stronger metallic bonding.
Therefore, the element Cs has the highest melting point among Rb, K, Li, Na, and Cs.