Name two elements whose properties were predicted on the basic of their positions in Mendeleev’s periodic table.

Name two elements whose properties were predicted on the basis of their positions in Mendeleev’s periodic table.

The three elements predicted by Mendeleev from the gaps in his periodic table were known as eka- boron, eka-aluminium and eka – silicon. What names were given to these elements when they were discovered later on ?

State one example of a Dobereiner’s triad’s showing in it that the atomic mass of middle element is half-way between those of the other two.

Which group of elements could be placed in Mendeleev’s periodic table later on, without disturbing the original order ? Give reason.