Answer: C-Li bonds are more covalent and have more ionic character; Li is more electropositive than Mg.
- A C-Li bonds are more covalent and have more ionic character; Li is more electropositive than Mg
- B Lithium is generally a noticeably heavier element than magnesium overall as widely reported
- C RLi compounds exist as largely ionic crystalline salts dissolved in solution in standard practice
- D Magnesium is a more electronegative element than lithium in these compounds under most conditions encountered
Correct answer: A. C-Li bonds are more covalent and have more ionic character; Li is more electropositive than Mg
Explanation: RLi has more polarised C-Li bond (Li more electropositive than Mg, less electronegative), making the carbanion character stronger and RLi more nucleophilic/basic.
Each s-block metal ion emits a characteristic flame colour because heating excites electrons to higher energy levels; light is emitted as they fall back, with the colour determined by the specific energy gap.
Concept context
Group 1 (alkali metals) and Group 2 (alkaline earth metals). Learn their reactions with water and air, important compounds like NaOH, Na₂CO₃, and CaCO₃, and anomalous behaviour of lithium and beryllium.