The binding energy of an electron in the ground state of He is equal to . The energy required to remove both the electrons is:
Helium atom has 2 electrons. When one electron is removed, the remaining atom is hydrogen like atom, whose energy in first orbit is
Therefore, to remove the second electron from the atom an additional energy of is required.
Hence, total energy required to remove both the electrons .
Study 40% syllabus and score up to 100% marks in JEE
5 g of Na2SO4 was dissolved in x g of H2O. The change in freezing point was found to be 3.820C. If Na2SO4 is 81.5% ionised, the value of x (K
A capacitor is made of two square plates each of side 'a' making a very small angle
A solution of m-chloroaniline, m-chlorophenol and m-chlorobenzoic acid in ethyl acetate was extracted initially with a saturated solution of NaHCO3 to give fraction A. The leftover organic phase was extracted with d