901. Modern periodic table has been divided in ___________ blocks?
A. 2
B. 4
C. 8
D. 7
902. Amphoteric exides are those which possess ____________ properties?
A. Acidic
B. Basic
C. Acidic and basic
D. Neutral and acidic
903. Hydrogen resembles with carbon because of having________________?
A. Same number of electrons in the valence shell
B. Similar physical state
C. Remarkable reducing properties
D. Homovalent (show same valency)
904. In which of the following pairs are elements belonging to the same group ?
A. Boron & Beryllium
B. Nitrogen & Phosphorous
C. Magnesium & Aluminium
D. Gallium & Helium
905. Which one of the following is not a periodic property ?
A. Melting point of elements
B. Boiling point of elements
C. Ionization energy of elements
D. Coordination number of ions
906. Which discovery caused a revision in the periodic law as stated by Mendeleev ?
A. Location of nucleus by Rutherford
B. Atomic number by Moseley
C. X-rays by Roentgen
D. Natural radioactivity by Henry Bacquerel.
907. The property which increases upto group IV-A then decreases on wards_______________?
A. Ionization energy
B. Atomic radii
C. Melting & boiling points
D. Atomic volume
908. Deuterium reacts with oxygen to form________________?
A. Hard water
B. Heavy water
C. Soft water
D. Water gas
909. Ionization energy depends upon____________________?
A. Nuclear charge
B. Atomic size
C. Shielding effect
D. I.E depends upon all of the above and nature of orbital
910. Addition of 2nd electron to a uni negative ion is always____________________?
A. Exothermic
B. Endothermic
C. Data is insufficient
D. Unpredictable