Which of the following elements conduct electricity and also melts below 100°C ?
Correct answer: B. Sodium
- A. Aluminium
- B. Sodium
- C. Carbon
- D. Sulphur
Explanation
Sodium is a metal, so its delocalised electrons allow it to conduct electricity, and its melting point is about 97.8 °C, just below 100 °C. Aluminium also conducts electricity but melts at about 660 °C, while carbon and sulfur do not satisfy both conditions. The likely mistake is choosing aluminium because it is a familiar good conductor without checking its melting point.
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About Periodic Properties and Trends
Periodic properties arise from electron configuration and effective nuclear charge, producing trends in atomic and ionic radius, ionization energy, electron affinity, electronegativity, metallic character and reactivity. Comparisons run across periods and down groups, with attention to common exceptions. The topic also relates these trends to the behavior of s-block and p-block elements.
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