The high reactivity of fluorine is due to
The main chemical constituent of clay is
The major constituent of air is
The iron ore magnetite consists of
The ionisation energy of hydrogen atom in the ground state is x KJ. The energy required for an electron to jump from 2nd orbit to 3rd orbit is
The mineral containing both magnesium and calcium is
The metal does not give H2 on treatment with dilute HCL is
The number of g-molecule of oxygen in 6.02 x 1024CO molecules is
The most extensive, commercially useful source of thorium as monazite sand occurs in India at
The main active constituent of tea and coffee is
The maximum number of isomers for an alkene with molecular formula C4H8 is
The hardest form of carbon is
The number of electrons presents in H+ is
H+ is a hydrogen ion, and it is an ion because it LOST an electron. Electrons are negatively charged. When an atom gains electrons it will have NEGATIVE charges.
So it has zero electron.
The most important ore of aluminium is
The organic reaction represented by equation CH3 - CH = O + H2NOH gives CH3 - CH - NH + H2O is an example of
The hottest part of the gas flame is known as
The isomerism which exists between CH3CHCI2 and CH2CI. CH2CI is
The human body is made up of several chemical elements; the element present in the highest proportion (65%) in the body is
The half life period of an isotope is 2 hours. After 6 hours what fraction of the initial quantity of the isotope will be left behind?
The number of atoms present in 21.6 gram of silver (atomic weight = 108) are same as the molecules in
The number of atoms present in 21.6 gram of silver (atomic weight = 108) are same as the molecules in 12 moles of KMnO4.
The National Chemical Laboratory is situated in
Equal masses of oxygen, hydrogen and methane are kept under identical conditions. The ratio of the volumes of gases will be
The mass number of an atom is equal to
The number of waves made by an electron moving in an orbit having maximum magnetic quantum number is +3
The method of concentrating the ore which makes use of the difference in density between ore and impurities is called