19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Assertion: Manganese (atomic number 25) has a less favorable electron affinity than its neighbors on either side. Reason: The magnitude of an element’s electron affinity depends on the element’s valence shell electron…
The statement that is not correct for periodic classification of elements is:
The order of screening effect of electrons of s, p, d and f orbitals of a given shell of an atom on its outer shell electrons is:-
If the Aufbau principle had not been followed, Ca (Z = 20) would have been placed in the:
An element with lowest ionization energy in their respective period is
Which of the following isoelectronic ions has the lowest ionization energy?
The most ionic compound will be formed between:
IE1 and IE2 of Mg(g) are 178 and 348 kcal mol–1 respectively. The energy required for the reaction Mg (g) ® Mg²⁺ (g) + 2e– is
Of the following orders of relative sizes, choose the incorrect order
The element with highest I.E. is:
Consider the isoelectronic species, Na⁺, Mg²⁺,F –and O₂–. The correct order of increasing length of their radii is ...........
The element with lowest electron gain enthalpy is:
From which of the following species it is easiest to remove one electron?
Consider the following statements: (I) The radius of an anion is larger than that of the parent atom. (II) The ionization energy generally increases with the increasing atomic number in a period. (III) The electronega…
Which of the following properties shows a gradual decrease with an increase in atomic number across a period in the periodic table?
Assertion: Third ionization energy of sulphur is larger than phosphorous. Reason: There is a larger amount of stability associated with filled s- and p- sub-shells (a noble gas electron configuration) which correspond…
A, B, and C are hydroxy-compounds of the elements X, Y, and Z respectively. X, Y, and Z are in the same period of the periodic table. A gives an aqueous solution of pH less than seven. B reacts with both strong acids …
Assertion: Boron has a smaller first ionization enthalpy than beryllium. Reason: The penetration of a 2s electron to the nucleus is more than the 2p electron hence 2p electron is more shielded by the inner core of ele…
Second electron affinity
The lower electron affinity of fluorine than that of chlorine is due to
Assertion: Generally, ionization enthalpy increases from left to right in a period. Reason: When successive electrons are added to the orbitals in the same principal quantum level, the shielding effect of the inner co…
La (Lanthanum) having atomic number 57 is a member of:
Assertion: Electron gain enthalpy becomes less negative as we go down a group. Reason: The size of the atom increases on going down the group and the added electron would be farther from the nucleus.
The ionization energy of boron is less than that of beryllium because :
Assertion : PbI₄ is a stable compound. Reason : Iodide stabilizes higher oxidation state.