Chapter: Classification of Elements and Periodicity in Properties

The atomic number of the element unnilennium is:

The atomic number of Unnilunium is ______ .

The group number, number of valence electrons, and valency of an element with atomic number 15, respectively, are:

The IUPAC symbol for the element with atomic number 119 would be:

The element with Z=120 (not yet discovered) will be an/a:

Similarity in chemical properties of the atoms of elements in a group of the periodic table is most closely related to:

According to the periodic law of elements, the variation in properties of elements is related to their

The set that contains atomic numbers of only transition elements, is:

The correct order of the ionic radii of \( {{O}^{{2}}},{{N}^{{3}}},{{F}^{-}},M{{g}^{{2+}}},N{{a}^{+}}\And A{{l}^{{3+}}}\)is:

The elements with atomic numbers 101 and 104 belong to, respectively:

The process that is NOT endothermic in nature is:

The ionic radii of \( {{O}^{{2-}}},{{F}^{-}},N{{a}^{+}}\,\And \,M{{g}^{{2+}}}\)   are in the order:

Among the statements (I – IV), the correct ones are:
(I) Be has smaller atomic radius compared to Mg.
(II) Be has higher ionization enthalpy than Al.
(III) Charge/radius ratio of Be is greater than that of Al.
(IV) Both Be and Al form mainly covalent compounds.

The five successive ionization enthalpies of an element are 800, 2427, 3658, 25024 and 32824 kJ\(\begin{align}mo{{l}^{{-1}}}\end{align}\). The number of valence electrons in the element is :

In general, the property (magnitudes only) that shows an opposite trend in comparison to other properties across a period is:

Three elements X, Y and Z are in the \(\begin{align}{{3}^{{rd}}}\end{align}\) period of the periodic table. The oxides of X, Y and Z, respectively, are basic, amphoteric and acidic. The correct order of the atomic numbers of X, Y and Z is:

B has a smaller first ionization enthalpy than Be. Consider the following statements:
(I)it is easier to remove 2p electron than 2s electron
(II)2p electron of B is more shielded from the nucleus by the inner core of electrons than the 2s electrons of Be
(III)2s electron has more penetration power than 2p electron
(IV)atomic radius of B is more than Be (atomic number B = 5, Be = 4)
The correct statements are:

The acidic, basic and amphoteric oxides, respectively, are:

The first and second ionisation enthalpies of a metal are 496 and 4560 \(\begin{align}kJmo{{l}^{{-1}}}\end{align}\) , respectively. How many moles of HCl and \(\begin{align}{{H}_{2}}S{{O}_{4}}\end{align}\), respectively, will be needed to react completely with 1 mole of the metal hydroxide?

The first ionization energy (in kJ/mol) of Na, Mg, Al and Si respectively, are:

The increasing order of the atomic radii of the following elements is:
(i) C
(ii) O
(iii) F
(iv) Cl
(v) Br

The electron gain enthalpy (in kJ/mol) of fluorine, chlorine, bromine and iodine, respectively, are:

Within each pair of elements F & Cl, S & Se, and Li & Na, respectively, the elements that release more energy upon an electron gain are:

In comparison to boron, berylium has:

The element having greatest difference between its first and second ionization energies, is:

The correct order of the atomic radii of C, Cs, Al, and S is:

The correct option with respect to the Pauling electronegativity values of the elements is:

The \(\begin{align}{{71}^{{st}}}\end{align}\) electron of an element X with an atomic number of 71 enters into the orbital:

In general, the properties that decrease and increase down a group in the periodic table, respectively, are:

When the first electron gain enthalpy(\(\begin{align}{{\Delta }_{{eg}}}H\end{align}\)) of oxygen is – 141 kJ/mol, its second electron gain enthalpy is:

The correct order of electron affinity is:

For \( N{{a}^{+}},M{{g}^{{2+}}},{{F}^{-}}\,\,and\,{{O}^{{2-}}}\); the correct order of increasing Ionic radii is:

Both lithium and magnesium display several similar properties due to the diagonal relationship; however, the one which is incorrect is:

The group having isoelectronic species is:

Consider the following ionization enthalpies of two elements ‘A’ and ‘B’.

Which of the following statements is correct?

The electronic configuration with the highest ionization enthalpy is:

Which of the following atoms has the highest first ionization energy?

The following statements concern elements in the periodic table. Which of the following is true?

The ionic radii (in Å) of are respectively:

In the long form of the periodic table, the valence shell electronic configuration of \(\begin{align}5{{s}^{2}}5{{p}^{4}}\end{align}\) corresponds to the element present in:

Which of the following series correctly represents relations between the elements from X to Y? \(\begin{align}X\to Y\end{align}\)

Which of the following arrangements represents the increasing order (smallest to largest) of ionic radii of the given species\({{O}^{{2-\text{ }}}},{{S}^{{2-}}},{{N}^{{3-}}},{{P}^{{3-}}}\)?

Which one of the following has largest ionic radius?

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

The order of increasing sizes of atomic radii among the elements O, S, Se and As is:

Which is the correct order of second ionization potential of C, N, O and F in the following?

The electron affinity of chlorine is 3.7 eV. 1 gram of chlorine is completely converted to \(\begin{align}C{{l}^{-}}\end{align}\) ion in a gaseous state. (1 eV = 23.06 kcal\(\begin{align}mo{{l}^{{-1}}}\end{align}\)). Energy released in the process is

In which of the following arrangements, the sequence is not strictly according to the property written against it?

Which among the following elements has the highest first ionization enthalpy?

The correct order of electron gain enthalpy with negative sign of F, Cl, Br and I, having atomic numbers 9, 17, 35 and 53 respectively, is:

The correct sequence which shows decreasing order of the ionic radii of the elements is

Following statements regarding the periodic trends of chemical reactivity of alkali metals and halogens are given. Which of these statements gives the correct picture?

The increasing order of the first ionization enthalpies of the elements B, P, S and F (Lowest first) is

Which of the following oxides is amphoteric in character?

In which of the following arrangements, the order is NOT according to the property indicated against it?

Which one of the following ions has the highest value of ionic radius?

Among \(\begin{align}A{{l}_{2}}{{O}_{3}},\text{ }Si{{O}_{2}},\text{ }{{P}_{2}}{{O}_{3}}\text{ }and\text{ }S{{O}_{2}}\end{align}\) the correct order of acid strength is

The formation of the oxide ion \end{align}\)latex {{O}^{{2-}}}\left( g \right)\end{align}\)requires first an exothermic and then an endothermic step as shown below
\(\begin{align}O(g)+{{e}^{-}}={{O}^{-}}(g)\Delta {{H}^{0}}=-142kJmo{{l}^{{-1}}}\end{align}\)
\(\begin{align}{{O}^{-}}(g)+{{e}^{-}}={{O}^{{2-}}}(g)\Delta {{H}^{0}}=844kJmo{{l}^{{-1}}}\end{align}\)
This is because

Which one of the following is an amphoteric oxide?