Long Q/A Periodic Table and Periodicity of Properties

Explain the position and properties of alkali metals and halogens in the periodic table. Why do they react so easily with each other?

Alkali metals, found in Group 1 of the periodic table, are highly reactive, soft metals with low melting points. They have one electron in their outermost shell, which they easily lose to form positive ions (cations). Examples include lithium (Li), sodium (Na), and potassium (K). Halogens, found in Group 17, are highly reactive nonmetals with … Read more

Describe the significance of Mendeleev’s periodic law and how it helped in the development of the modern periodic table.

Mendeleev’s periodic law stated that the properties of elements are a periodic function of their atomic masses. By arranging elements in order of increasing atomic mass, Mendeleev noticed that elements with similar properties occurred at regular intervals. He also predicted the existence and properties of elements that had not yet been discovered, based on gaps … Read more

Explain the trends of atomic size, ionization energy, and electron affinity in the periodic table with suitable examples.

In the periodic table, atomic size decreases as you move across a period from left to right. This happens because as the nuclear charge increases, electrons are pulled closer to the nucleus, reducing the size of the atom. For example, the atomic radius of sodium (Na) is larger than that of chlorine (Cl). Ionization energy, … Read more

In which block, group, and period in the periodic table would you place each of the following elements with the given electronic configurations?

(a) 1s², 2s¹: Block: s-block, Group: 1, Period: 2(b) 1s², 2s², 2p⁶: Block: p-block, Group: 18, Period: 2(c) 1s², 2s², 2p⁶, 3s¹: Block: s-block, Group: 1, Period: 3(d) 1s¹: Block: s-block, Group: 1, Period: 1 Related Questions: Arrange the elements in each of the following in order of decreasing shielding effect: Specify which of the … Read more

Write the valence shell electronic configuration of the atoms of the following elements:

(a) An element present in period 3 of Group VA: Arsenic (As) – 3s² 3p³(b) An element present in period 2 of Group VIA: Oxygen (O) – 2s² 2p⁴ Related Questions: Write the valence shell electronic configuration for the following groups: Write the valence shell electronic configuration of an element present in the 3rd period … Read more

Write the valence shell electronic configuration for the following groups:

(a) Alkali metals: ns¹(b) Alkaline earth metals: ns²(c) Noble gases: ns² np⁶(d) Halogens: ns² np⁵ Related Questions: Write the valence shell electronic configuration of the atoms of the following elements: Write the valence shell electronic configuration of an element present in the 3rd period and Group IIA. Arrange the elements in each of the following … Read more

Arrange the elements in groups and periods from Q. No. 6:

Groups: IIA: B IVA: None VA: E, G VIA: C, H VIIA: None Periods: Period 1: A, D Period 2: B, C, F Period 3: E, G, H Related Questions: Arrange the elements in each of the following in order of decreasing shielding effect: Specify which of the following elements you would expect to have … Read more

Electronic configurations of some elements are given below. Group the elements in pairs that would represent similar chemical properties:

A = 1s², 2s¹B = 1s², 2s², 2p⁶C = 1s², 2s², 2p³D = 1s¹E = 1s², 2s², 2p⁶, 3s², 3p³F = 1s², 2s²G = 1s², 2s², 2p⁶, 3s¹H = 1s², 2s², 2p⁴, 3s² Pairs representing similar chemical properties: A and D (Both are in Group I, alkali metals) B and F (Both are noble gases) … Read more

Specify which of the following elements you would expect to have the greatest electron affinity: S, P, Cl

Chlorine (Cl) has the greatest electron affinity. This is because chlorine has a high tendency to gain an electron to complete its valence shell, as it is only one electron away from achieving a stable noble gas configuration. Related Questions: Arrange the elements in each of the following in order of decreasing shielding effect: Write … Read more