19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The basis of modern periodic table is
Which of the following is incorrect explanation about Mendeleev’s periodic law ?
Mendeleev left the gap under aluminum and a gap under silicon and called these elements Eka-Aluminium and……A……Here, A refers to
According to Mendeleev, elements are arranged in order of their increasing ……A….Here, A refers to
Lothar Meyer drew a graph showing the relation between
Lothar Meyer plotted the physical properties such as atomic volume, melting point and ….A…..against atomic weight. Here, A refers to
According to Alexander Newlands, elements are arranged in…..A….order of their atomic weights. Here A refers to
John Alexander Newlands relationship referred to as the …….A…… Here, A refers to
The stability of +1 oxidation state increases in the sequence (AIPMT 2009)
Assertion: Coloured cations can be identified by borax bead test. Reason: Transparent bead (NaBO2 + B2O3) forms coloured bead with coloured cation. (AIIMS 2009)
White lead is (CPMT 2007)
Supercritical CO2 is used as (AIIMS 2007)
Litharge is chemically (AIIMS 2007)
For which one of the following minerals, the composition given is incorrect? (Kerala CEE 2007)
In borax bead test which compound is formed? (Punjab PMET 2007)
Value of x in potash alum, K2SO4.Alx (SO4)3 . 24H2O is (CPMT 2007)
Which glass will not crack when temperature changes ? (DUMET 2006)
The number of isomers possible for disubstituted borazine, B3N3H4X2 is: (AIPMT 2006)
The colour imparted by Co(II) compounds to glass is (AIIMS 2006)
Assertion: Silicones are hydrophobic in nature. Reason: Si–O–Si linkages are moisture sensitive. (AIIMS 2006)
Percentage of lead in lead pencil is (AIPMT 1999)
Which of the following does not show electrical conduction? (AIPMT 1999)
In graphite, electrons are
Boron compounds behave as Lewis acids, because of their (AIPMT 1996)
Aluminium (III) chloride forms a dimer because Aluminium (AIPMT 1995)