Question

1)with relevant equation suggest three methods of preparing hydrogen using the following
zinc, acidified water,6v battery, dilute Hydrochloric acid, Red hot iron, steam

2)why did Mendeleev left some gaps in his periodic table? give example for such gaps​

Answer 1

Answer:

mendeleev left some gaps in his periodic table because he believed that in future more elements will be discovered

Explanation:

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