Question

2 this table provides information about some group 1 elements.which is the best estimate of the melting point of rubidium (rb)?a 25°cb 40°cc 75°cd 184°c

Explanation:

Step1: Analyze the trend of melting points in Group 1 elements

As we move down Group 1 (from Li to Fr), the melting point generally decreases. The melting points of Li ($181^{\circ}C$), Na ($98^{\circ}C$), K ($63^{\circ}C$), Cs ($29^{\circ}C$), Fr ($27^{\circ}C$) show a decreasing trend. Rubidium (Rb) is between K ($63^{\circ}C$) and Cs ($29^{\circ}C$).

Step2: Estimate the melting point of Rb

Since the trend is a decrease in melting point down the group, the melting point of Rb should be between $29^{\circ}C$ and $63^{\circ}C$. Among the options, $40^{\circ}C$ (Option B) is the value that lies within this range.

Answer:

B. $40^{\circ}C$