List of top Chemistry Questions on Classification of elements and periodicity in properties

Identify correct orders with respect to properties:
I. B < Al < Mg < K (metallic character)
II. Si < P < C < N (electronegativity)
III. Si < C < N < F (non-metallic character)
IV. Al < Mg < S < P (ionization enthalpy)

If $v_0$ is threshold frequency and $v$ is incident frequency, velocity of photoelectrons is:

Which of the following statements are NOT correct?
I. Addition of electron to a gaseous atom is always exothermic.
II. Removal of electron from gaseous atom is always endothermic.
III. First ionization enthalpy of oxygen is greater than nitrogen.
IV. In group I elements lithium is least electropositive.

The atomic numbers of four elements A, D, E, G are 4, 7, 8, 12 respectively. The decreasing order of electronegativity of these elements is

Identify the two ions having the highest and lowest length of ionic radius respectively out of the following: \[ F^{-},\quad Mg^{2+},\quad Na^{+},\quad O^{2-} \]

The atomic number of the element with systematic name of Ununnilium is

The element with atomic number 114 has outer shell electron configuration as that of element 'X'. What is X?

Consider the following oxides: $\text{SO}_2$, $\text{P}_2\text{O}_5$, $\text{SO}_3$, $\text{Al}_2\text{O}_3$, $\text{K}_2\text{O}$, MgO. The most acidic and most basic oxides are respectively:

Which family does sodium belong to?

Match List – I with List – II:

Choose the correct answer from the options given below.

Which of the following statement is incorrect about the periodic trend?

Which of the following represents the correct increasing order of first ionization enthalpy for Ca, Ba, S, Se and Ar?

Match the following

Identify the correct orders regarding atomic radii
i. $\text{Cl}>\text{F}>\text{Li}$
ii. $\text{P}>\text{C}>\text{N}$
iii. $\text{Tm}>\text{Sm}>\text{Eu}$
iv. $\text{Sr}>\text{Ca}>\text{Mg}$

In hydrogen atom, an electron is transferred from an orbit of radius $1.3225$ nm to another orbit of radius $0.2116$ nm. What is the energy (in J) of emitted radiation? (Rydberg constant $R_H \approx 1.097 \times 10^7 \text{ m}^{-1}$)

In second period of the modern periodic table, two elements X and Y have higher first ionization enthalpy values than the preceding and succeeding elements. X and Y are respectively

Consider the following pairs of elements and identify the pairs of elements which have nearly same atomic radius. I. Y, La II. Zr, Hf III. Mo, W IV. Cr, Mo

Work functions of four metals M$_1$, M$_2$, M$_3$ and M$_4$ are 4.8, 4.3, 4.75 and 3.75 eV respectively. The metals which do not show photoelectric effect when light of wavelength 310 nm falls on the metals are

Among the following the isoelectronic species are
I. $Mg^{2+}, Al^{3+}, F^-$
II. $O^{2-}, F^-, N^{3-}$
III. $K^+, Ca^{2+}, Sc^{3+}$
IV. $Mn^{2+}, Fe^{3+}, V^{3+}$

In long form of periodic table an element 'X' is present in group 'Y' in which Mn is also an element. X, Y respectively are

Among Li, Na, O, S, the elements having the most negative electron gain enthalpy and least negative electron gain enthalpy respectively are:

In Sr (Z=38), the number of electrons with \(l=0\) is x, number of electrons with \(l=2\) is y. \((x-y)\) is equal to (\(l\) = Azimuthal quantum number)

Observe the following data (\(\Delta_i H_1\), \(\Delta_i H_2\) and \(\Delta_{eg}H\) represent the first, second ionisation enthalpies and electron gain enthalpy respectively).

Using the data identify the most reactive metal.