19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The period number in the long form of the periodic table is equal to
The statement that is not correct for periodic classification of elements is:
If the Aufbau principle had not been followed, Ca (Z = 20) would have been placed in the:
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:-
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…
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…
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…
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…
The ionization energy of boron is less than that of beryllium because :
From which of the following species it is easiest to remove one electron?
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
Which of the following isoelectronic ions has the lowest ionization energy?
Consider the isoelectronic species, Na⁺, Mg²⁺,F –and O₂–. The correct order of increasing length of their radii is ...........
Of the following orders of relative sizes, choose the incorrect order
La (Lanthanum) having atomic number 57 is a member of:
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…
The most ionic compound will be formed between:
The electronic configurations of the elements X, Y, Z, and J are given below. Which element has the highest metallic character?
An element with lowest ionization energy in their respective period is
For a given value of n (principal quantum number), ionization energy is highest for
Second electron affinity
The lower electron affinity of fluorine than that of chlorine is due to
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:-
Of the following which will have the minimum atomic radius?
Which of the following represents an excited state of an atom?