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प्रश्न
An element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following
पर्याय
Mg
Na
P
Ca
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उत्तर
Na
Explanation -
Sodium is a third-period alkali metal which is a soft metal and highly reactive. sodium is stored under kerosene and whenever it comes in contact with air or water it reacts vigorously.
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| \[\begin{array}{cc}\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\\ |\phantom{....}|\phantom{....}|\\\ce{H - C - C - C - H}\\ |\phantom{....}|\phantom{....}|\\\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H} \end{array}\] |
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