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

In which of the following compounds, the size of manganese is maximum?

Which of the following is an endothermic process? \((g=\text{gas})\)

Observe the given two statements about \(\alpha\)-particle experiment and Rutherford assumptions. Statement-I: The ratio of atomic radius to its nuclear radius is \(10^5\). Statement-II: In an atom, the majority of the space is vacant. The correct answer is

Which of the following statement is correct?

Which of the following orders are correct for the stated property?

Match the following.

The wavelength of electron in the orbit X of hydrogen atom is \(6\pi a_0\). What is the value of X? (\(a_0=\) radius of first orbit of hydrogen atom)

Identify the pairs in which electron gain enthalpy of the first element is more than that of the second element. \[ \text{I. } F,\ Br \] \[ \text{II. } Na,\ Li \] \[ \text{III. } S,\ O \]

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.

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

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)

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