Question

explain any 4 periodic properties in periodic table.​

Answer 1

Answer:

Explanation:

Answer:-

• Atomic Radius:-
• As we move across the period , the atomic size decreases. This is because of increase in effective nuclear charge.
• As we move down a group, atomic size increases. This is due to increase in distance between the nucleus and outermost valence shell and decrease in effective nuclear charge.
• Metallic Charge:-
• Metallic charge increases down a group, due to decrease in nuclear charge.
• Metallic character decreases as we move across a group, vice versa.

Let's Turn to history:-

• The first classification term by Lavoisier, hint to classify given by Dalton.
• First table made by Dobereiner, called Dobereiner's Triads.
• Then, Newlands' laws of Octaves.
• Father of Periodic Table is Mendeleev, almost successful periodic table given by him.
• Niels Bohr made the modern periodic table.

Statements:-

The properties of elements are the periodic functions of the atomic numbers. [Modern Periodic Table] $.$

The properties of elements are the periodic functions of the atomic masses. [Mendeleev's Periodic Table] $.$

Answer 2

Answer :-

$\:\:\:\underline{\boxed{\sf{\blue{The \: periodic \: properties \: in \: periodic \: table \: are \: as \: follows \: }}}}$

✒ Atomic Radius - This is the distance between the nucleus to the electron in last shell of an isolated atom. This trend shows that when we go down the group, atomic radius increases whereas when we go from left to right of the period, it decreases. This happens in going down the group because the inner energy levels are filled with electrons, which serve to shield the outer electrons from the pull of nucleus. Consequently the size of the atom increases as reflected in the atomic radii. And for period, we know that electrons get added up in the same shell. This increases the net effective nuclear charge to hold those electrons, so the size decreases as nucleus pulls she near to it.

✒ Ionic Radius - The ionic radii is the distance between cations and anions in ionic crystals. The ionic radius show same trend as atomic radius. A cation is smaller than its parent atom because it had fewer electrons while the nuclear charge remains same whereas an anion has larger size than parent atom because an electron is added which results in greater repulsion and thus decreases the nuclear charge.

✒ Ionization Enthalpy - This is the quantitative measure of the tendency of an element to loose electron is given as its Ionization Enthalpy.

It represents the energy required to remove electrons from an isolated gaseous atom (X) in its ground state. The first ionization enthalpy of this atom will be given as :-

$\bold{X}_{(g)} \: \: \longrightarrow \: \bold{X^{+}}_{(g)} + \bold{e^{-}}$

The second ionization enthalpy is greater than the first and this trend continues on.

It increases across the period and decreases down the group.

Ionization Enthalpies are maxima at the noble gases which have closed electron shells and very stable electronic configuration.

✒ Electron Gain Enthalpy - When an electron is added to a neutral gaseous atom (X) to convert it into a negative ion, the enthalpy change accompanying process is defined as the Electron Gain Enthalpy (∆ H).

Electron gain enthalpy provides a measure of the case with which an atom adds an electron to form anion is given by,

$\bold{X}_{(g)} \: + \: \bold{e^{-}} \: \: \longrightarrow \: \: \bold{X^{-}}_{(g)}$

Depending on the element, the process of adding an electron to the atom can be either endothermic or exothermic.

Electron gain enthalpy becomes more negative as we move left to right across a period. That is ut increases across a period and decreases when we go down the group.

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★ Supplementary Artefacts :-

• If the energy is released when an electron is added to an atom, the electron affinity is taken as positive. If energy has to be supplied to add an electron to an atom, then the electron affinity of the atom is given as positive.

• Metallic Character increases as we go down the group, this is because the atom gain more tendency to loose electrons to achieve nearest noble gas configuration.

• Non - Metallic Character increases as we move left to right across a period, as the atoms gain higher tendency to gain an electron to achieve the nearest noble gas configuration.

• Modern Periodic Law :- The chemical and physical properties of an element is the periodic function of its atomic number.

• Mendeleev's Periodic Law :- The properties of the elements are a periodic function of their atomic weights/masses.

• Modern Periodic Table :- Henry Moseley observed regularities in characteristic X - ray spectra of the elements. A plot of √v (v is the frequency of X - rays emitted) against atomic number (z) gave a straight line and not the plot of √v vs. atomic mass.