Ask & Answer: India's Largest Education Community

8.30 

Actinoid Contraction > Lanthanoid contraction

Lanthanoids show lanthanoid contraction due to which their size is quite small as compared to actinoids although there is actinoid contraction also lanthanoid contraction has more impact on elements as there is one shell less than actinoids, so lanthanoids have less tendency to lose an electron and to undergo any reaction like the formation of oxide etc.

The Kerala Plus one admission 2025 fee is given below.

In the first semester of the MSc programme at Nagaland University – Kohima Campus, students focus on core foundational subjects. The curriculum includes Geomorphology and Remote Sensing, Structural Geology and Geodynamics, Palaeontology, and Mineralogy. These subjects provide a strong academic foundation and essential skills required for more specialised geological topics in the later semesters.

8.28 Metal ions which have valence electrons in d-orbital and in which d-d transition can take place will be coloured and the metal ions which have completely filled orbital or have d- orbital will be colourless as no d-d transition is possible in those configurations.

From the above table, it can be observed that only Sc³⁺ and Cu⁺ have either completely filled d- orbital or empty d-orbital. So, all other ions except Sc³⁺ and Cu⁺ will be coloured in aqueous solution because of absorption of radiations which fall in the visible region as on obtaining energy electrons jump from one d-orbital to another.

The Kerala plus one trial allotment was conducted on May 24, 2025. 

• Visit the official website of HSCAP at hscap.kerala.gov.in.
• Click on HSCAP Kerala Plus One trial allotment list link available on the home page.
• A new page will be opened.
• Enter the login details.
• Click on submit.
• Allotment details will be displayed.

8.25 K₂Cr₂O₇ acts as a very strong oxidizing agent in acidic medium. K₂Cr₂O₇ gets reduced and acts as an oxidizing agent by oxidizing Iodide to iodine

(i) K₂Cr₂O₇ oxidizes iodide to iodine

Cr₂O₇^2-+ 14H⁺+ 6e^-→ 2Cr³⁺ + 7H₂O

2I^-→ I₂ + 2e^- } x3

Overall: Cr₂O₇^2-+ 14H⁺+ 6I^-→ 2Cr³⁺ + 7H₂O+ 3I₂

(ii) K₂Cr₂O₇ oxidizes iron(II) to iron(III)

Cr₂O₇^2-+ 14H⁺+ 6e^-→ 2Cr³⁺ + 7H₂O

Fe²⁺→ Fe³⁺ + e^- } x6

Overall: Cr₂O₇^2-+ 14H⁺+ 6Fe²⁺→ 2Cr³⁺ + 7H₂O + 6Fe³⁺

(iii) K₂Cr₂O₇ oxidized H₂S to sulphur

Cr₂O₇^2-+ 14H⁺+ 6e^-→ 2Cr³⁺ + 7H₂O

H₂S → S + 2H⁺ + 2e^-} x3

Overall: Cr₂O₇^2-+ 8H⁺+ 3H₂S → 2Cr³⁺ + 7H₂O +3S

The Kerala Plus one trial allotment will be conducted on May 24, 2025. The first allotment will be published on June 2, second allotment on June 10, and the third allotment on June 16, 2025. 

8.23 In transition metals, it can be observed that the oxidation state of the metal varies from +1 to +7 which is obtained by removing all its valence electrons. In transition elements the oxidation state differ by 1 unlike non transition elements whose oxidation state differs by 2, for example in transition metals (Cu²⁺, Cu³⁺ and Fe²⁺, Fe³⁺) and In non-transition elements, this variation is selective, always differing by 2, e.g. S exhibits +2, +4, +6 oxidation states and N exhibits +3, + 5, etc.

For UG Diploma course admission, candidates must meet the eligibility criteria set by CII Institute of Hospitality - Taj Hotels, Chandigarh. Aspirants should pass Class 12 with 50% aggregate. The admission criteria for the course is entrance-based. Students must have cleared Class 12 from a recognised board in India with minimum 50% aggeragte. Added to that, candidate must pass class 12 with English as a subject.

8.22 Interstitial compounds are those compounds in which small atomic size elements like H, C, N occupy the interstitial sites of the crystal lattice of the Transition metal due to their large size.

Example, in the diagram given below:

Here, Green Balls form the Crystal lattice of transition metal and Blue balls represent elements like H/C/N which occupy the interstitial sites.

Kerala Plus one allotment 2025 will be done on June 2, second allotment on June 10, and the third allotment on June 16, 2025. Check the steps below.

• Visit the official website of HSCAP at hscap.kerala.gov.in.
• Click on HSCAP Kerala Plus One first allotment list link available on the home page.
• A new page will open where candidates will have to enter the login details.
• Click on submit and check the allotment details.

8.20 +3 oxidation state is the most common oxidation state of lanthanides i.e., Ln (III) compounds are predominant. +2 and +4 oxidation states can also be found in the solution or in solid compounds, but are not predominant.

CII Institute of Hospitality - Taj Hotels, Chandigarh offers three Diploma courses in the field of Hospitality Management. The duration of these courses is 18 months. Listed below are the CII Institute of Hospitality - Taj Hotels, Chandigarh courses specialisations:

• Swiss International Culinary Professional Diploma
• Swiss International Food & Beverage Service Professional Diploma
• Swiss International Rooms Professional Diploma