Measurement of exact radius not possible bcz: #we can only find probability i.e. #Total: 118 #Natural: 94 #Man Made: 24
approx. radius determined #atom doesn't exist independently [Except noble gases] Elements
#Non-Metals: 18 #Metalloids: 7 #Metals: 93
Half dist. btw nuclei of 2 like atoms in Covalent Doeberiemer aligned 3-3 1. Li,Na,K ✓
single covalent bond. rc=1/2 [Intrnclr dist] Radius elements vertically by atomic 2. Fe,Co,Ni ✕
Half dist btw nuclei of 2 adjacent metal atom(kernel) in lattice Metallic Radius
Atomic mass, with central element's 3.Cl,Br,I ✕
Radius Doeberiemer's mass being average of other 2. 4. Ca,Sr,Ba ✓
Half dist. btw nuclei of 2 non bonded neighboring atoms of 2 adjacent Vander-waal Triads
molecules with Vw attr'n force [btw opp. poles of induced dipoles] Radius LIMITATIONS:
#Triad classification doesn't apply to all known elements.
dist. btw centre of nucleus & point till nucleus' Ionic #Middle element's calculated mass differs from actual mass.
influence on outermost e-. Intrnclr dist=rc+ra Radius
When arranged by increasing atomic mass,
Atomic Radius Newland's 8th element exhibits properties like 1st.
Properties depending on electronic Periodic/ Octave
Ionization Energy/ Enthalpy conf'n of elements [Repeat after Atomic LIMITATION: Only Li-7 to Ca-40 are classified
regular interval:2,8,8,18,18,32,32] Properties
e- Affinity/ e- Gain Enthalpy MENDELEEV'S PERIODIC LAW: Physical & chemical
properties are periodic func'n of atomic masses.
Elements with completely filled penultimate shell. Representative
eg. s-block,p-block Elements LIMITATIONS: #Position of 'H' wasn't justified
2nd Periodic Classification Mendeleev's #Heavier element appears before lighter element
Elements with partially filled penultimate Transition Classification # Isotopes of same element display varying
Classifi'n
shell. eg. d-block except Cu,Zn,Cd,Hg,Pd,Au,Ag Elements
of PT and Periodic Properties positions in table due to their atomic mass
Elements with partially filled penultimate & Inner Transition Plus Point: He left empty space for
anti-penultimate shell. eg. all f-block elements Elements discovery of elements
Alkali Metals-ns¹ Ist/IA Group Mosley's formula √ʋ=A(Z-b) shows how
s-block Progress towards element's properties depend on atomic number.
Alkaline Earth Metals-ns² 2nd/IIA Group elements: ns¹⁻² long form of
Periodic Table MODERN PERIODIC LAW: Physical & chemical properties
Boron Family-ns²np¹ I3th/IIIA Group of elements are periodic func'n of atomic numbers
Carbon Family-ns²np² I4th/IVA Group s-block elements: Elements with last e- entering
s-subshell of outermost shell. IIA oxides &
Pnictogens[Poisonous]-ns²np³ I5th/VA Group p-block
hydroxides are basic & abundant in Earth's crust.
elements: 1st
Chalcogens[ores]-ns²np⁴ I6th/VIA Group ns²np¹⁻⁶ Classificat'n p-block elements: Elements with last e-
of PT-2 1st entering p-subshell of outermost shell.
Halogens[sea salts]-ns²np⁵ I7th/VIIA Group Classification of
PT-1 d-block elements: Elements with last e-
Noble/Inert Gases-ns²np⁶ I8th/0 Group entering d-subshell of penultimate(n-1) shell.
d-block elements: ns¹⁻²(n-1)d¹⁻¹⁰ f-block elements: Elements with last e- entering
f-subshell of anti-penultimate(n-2) shell.
Lanthanides[₅₇La- ₇₁Lu]: 6s²5d⁰⁻¹4f¹⁻¹⁴ 3rd G/6th P f-block elements:
3rd G/7th P ns²(n-1)d⁰⁻¹(n-2)f¹⁻¹⁴
Actinides[₈₉Ac- ₁₀₃Lr]: 7s²6d⁰⁻¹5f¹⁻¹⁴
approx. radius determined #atom doesn't exist independently [Except noble gases] Elements
#Non-Metals: 18 #Metalloids: 7 #Metals: 93
Half dist. btw nuclei of 2 like atoms in Covalent Doeberiemer aligned 3-3 1. Li,Na,K ✓
single covalent bond. rc=1/2 [Intrnclr dist] Radius elements vertically by atomic 2. Fe,Co,Ni ✕
Half dist btw nuclei of 2 adjacent metal atom(kernel) in lattice Metallic Radius
Atomic mass, with central element's 3.Cl,Br,I ✕
Radius Doeberiemer's mass being average of other 2. 4. Ca,Sr,Ba ✓
Half dist. btw nuclei of 2 non bonded neighboring atoms of 2 adjacent Vander-waal Triads
molecules with Vw attr'n force [btw opp. poles of induced dipoles] Radius LIMITATIONS:
#Triad classification doesn't apply to all known elements.
dist. btw centre of nucleus & point till nucleus' Ionic #Middle element's calculated mass differs from actual mass.
influence on outermost e-. Intrnclr dist=rc+ra Radius
When arranged by increasing atomic mass,
Atomic Radius Newland's 8th element exhibits properties like 1st.
Properties depending on electronic Periodic/ Octave
Ionization Energy/ Enthalpy conf'n of elements [Repeat after Atomic LIMITATION: Only Li-7 to Ca-40 are classified
regular interval:2,8,8,18,18,32,32] Properties
e- Affinity/ e- Gain Enthalpy MENDELEEV'S PERIODIC LAW: Physical & chemical
properties are periodic func'n of atomic masses.
Elements with completely filled penultimate shell. Representative
eg. s-block,p-block Elements LIMITATIONS: #Position of 'H' wasn't justified
2nd Periodic Classification Mendeleev's #Heavier element appears before lighter element
Elements with partially filled penultimate Transition Classification # Isotopes of same element display varying
Classifi'n
shell. eg. d-block except Cu,Zn,Cd,Hg,Pd,Au,Ag Elements
of PT and Periodic Properties positions in table due to their atomic mass
Elements with partially filled penultimate & Inner Transition Plus Point: He left empty space for
anti-penultimate shell. eg. all f-block elements Elements discovery of elements
Alkali Metals-ns¹ Ist/IA Group Mosley's formula √ʋ=A(Z-b) shows how
s-block Progress towards element's properties depend on atomic number.
Alkaline Earth Metals-ns² 2nd/IIA Group elements: ns¹⁻² long form of
Periodic Table MODERN PERIODIC LAW: Physical & chemical properties
Boron Family-ns²np¹ I3th/IIIA Group of elements are periodic func'n of atomic numbers
Carbon Family-ns²np² I4th/IVA Group s-block elements: Elements with last e- entering
s-subshell of outermost shell. IIA oxides &
Pnictogens[Poisonous]-ns²np³ I5th/VA Group p-block
hydroxides are basic & abundant in Earth's crust.
elements: 1st
Chalcogens[ores]-ns²np⁴ I6th/VIA Group ns²np¹⁻⁶ Classificat'n p-block elements: Elements with last e-
of PT-2 1st entering p-subshell of outermost shell.
Halogens[sea salts]-ns²np⁵ I7th/VIIA Group Classification of
PT-1 d-block elements: Elements with last e-
Noble/Inert Gases-ns²np⁶ I8th/0 Group entering d-subshell of penultimate(n-1) shell.
d-block elements: ns¹⁻²(n-1)d¹⁻¹⁰ f-block elements: Elements with last e- entering
f-subshell of anti-penultimate(n-2) shell.
Lanthanides[₅₇La- ₇₁Lu]: 6s²5d⁰⁻¹4f¹⁻¹⁴ 3rd G/6th P f-block elements:
3rd G/7th P ns²(n-1)d⁰⁻¹(n-2)f¹⁻¹⁴
Actinides[₈₉Ac- ₁₀₃Lr]: 7s²6d⁰⁻¹5f¹⁻¹⁴
