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Question
Write scientific reason.
Mendeleev kept vacant places in the periodic table.
Solution
- In Mendeleev’s periodic table, the elements are arranged in increasing order of their atomic masses such that chemically similar elements are placed together in a group.
- However, while arranging the elements, Mendeleev kept vacant places in the periodic table for elements not discovered till then.
- Three of these unknown elements were given the names eka-boron, ekaaluminium and eka-silicon from the known neighbours.
- The atomic masses of these elements were indicated as 44, 68 and 72, respectively. He also predicted their properties.
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