Periodic Table- Chemistry

who discovered the first scientific and systematic periodic table

• Henry Mosley

• Dmitri Mendeleev

• John Dalton

• sir Isaac Newton

choose the correct statement

• the vertical column in the periodic table is called period

• the vertical column in the periodic table is called group

• the horizontal row in the periodic table is not called period

• none of the above

how many groups are there in modern periodic table

• 8

• 9

• 18

• 17

alkali metals are kept in ........

• IIA

• IIIA

• IA

• 0

Number of valence electrons in halogens is ..........

• 1

• 4

• 3

• 7

Tags

NGSS.HS-PS1-1

D block elements are known as .............

• Actinides

• Transition elements

• Lanthanides

• Noble gases

In which block, does the element Iron stand?

• d block

• p block

• s block

• f block

Electronic configuration of phosphorus is ........

• 1s²2s²2p⁵3s²3p⁴

• 1s²2s²2p⁵3s²3p³

• 1s²2s²2p⁶3s²3p³

• 1s²2s²2p⁶3s²3p⁴

Tags

NGSS.HS-PS1-1

choose the metalloid element

• Alumunium

• Germanium

• Silver

• Helium

Which one is correct ?

• for electronegative elements, reactivity increases with decrease in atomic size in same group

• for electropositive elements, reactivity decreases with decrease in atomic size in same group

• for non metals, reactivity increases with decrease in atomic size

• all of the above