Based on the periodic trends of Group 1 elements, which of the following temperatures is most likely to be the melting point of rubidium (Rb\text{Rb}Rb), given that sodium (Na\text{Na}Na) melts at 98∘C98^\circ\text{C}98∘C and potassium (K\text{K}K) melts at 63∘C63^\circ\text{C}63∘C?
390∘C390^\circ\text{C}390∘C
39∘C39^\circ\text{C}39∘C
3.9∘C3.9^\circ\text{C}3.9∘C
−39∘C-39^\circ\text{C}−39∘C
75 exam-style questions on Edexcel GCSE Chemistry 7.1 Group 1, covering 7.1.1 Classifying elements by group in the periodic table and 7.1.2 Properties and reactions of the alkali metals. Each one has a worked solution and a mark scheme showing where the marks go.