Periodic classification of elements

Which one of the following is a Dobereiner Triad?

• Na,Ca,Al

• Li,Na,Ca

• Li,Na,K

• F,Cl,Br

In Newlands classification Periodicity of properties is lost after (a)   element.

In Mendeleev's Periodic Table how many periods and groups are present?

• 6 periods, 8 groups

• 6 groups, 8 periods

• 7 periods, 8 groups

• 7 groups, 8 periods

Newland classified ________ elements.

• 63

• 118

• 65

• 56

According to Mendeleev's periodic law, Properties of elements are periodic functions of their increasing (a)  

Eka silicone is now called

• Germanium

• Aluminium

• Gallium

• Scandium

In Mendeleev's periodic table, the position of (a)   was not defined

Mendeleef classified _______elements

• 56

• 63

• 65

• 36