Question
Write short note :
Inner-Transition Elements.

Answer

(i) Elements placed in two separate rows at the bottom of the periodic table are called inner transition elements.
(ii) They include two series of elements: Lanthanides series and Actinides series. They belong to f-block elements of Modern Periodic table.
(iii) 14 elements with atomic number 58 to 71 (Cerium to Lutetium) are called lanthanides. These elements are placed along with lanthanum (La=57) in group 3 and period 6 because of very close resemblance in properties between them.
(iv) 14 elements with atomic number 90 to 103 (Thorium to Lawrencium) are called actinides. These elements are placed along with actinium (AC=89) in group 3 and period 7 because of very close resemblance in their properties.
(v) They have last three shells incompletely filled.
(vi) All these elements are metals.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

 The mass of the earth is $6 \times 10^{24} kg$. The distance between the earth and the sun is $1.5 \times 10^{11} m$. If the gravitational force between the two is $3.5 \times 10^{22} N$, what is the mass of the sun? Use $G=6.7 \times 10^{-11} N m ^2 kg^{-2}$
Depending on electronic configuration the properties of the elements vary in different groups. Explain why?
What is a synapse? What happens at the synapse between two neurons? How are the messages carried across a synapse? Explain with the help of a labelled diagram.
Observe the given diagram and answer the following questions:

Image

i. What is the name of the given apparatus?
ii. Which phenomenon is studied with the help of this apparatus?
iii. What are the final temperatures in thermometers $T _1$ and $T _2$ ?
iv. At what temperature the density of water is maximum?
v. Give one example of the above phenomenon in nature.
A food chain consists of fish, larvae, phytoplanktons and birds. The level of pesticides in water in which the fish, larvae and phytoplanktons live is quite high.
  1. In which organisms the pesticides enter from the polluted water? What is this level of organisms known as?
  2. Which organism will have the maximum amount of pesticides accumulated through the food chain? What is this process known as?
  3. Write the food chain comprising all the organisms mentioned above.
  4. Which other organism you could write in place of bird in the above food chain?
What is electromagnetic induction? Who discovered it?
During the respiration of an organism A, 1 molecule of glucose produces 2 ATP molecules whereas in the respiration of another organism B, 1 molecule of glucose produces 38 ATP molecules.
  1. Which organism is undergoing aerobic respiration?
  2. Which organism is undergoing anaerobic respiration?
  3. Which type of organism, A or B, can convert glucose into alcohol?
  4. Name one organism which behaves like A.
  5. Name two organisms which behave like B.
Saturated hydrocarbons are classified into three types. Write these names giving one example each.
The chemical substance P is made and secreted by the meristematic tissue at the tip of stem (or shoot) of a plant. The chemical substance P is responsible for a phenomenon Q in plants in which the stem bends towards a source of light. The same chemical substance P has an opposite effect on the root of a plant. It causes the root of a plant to bend away from the source of light in a process called R.
  1. What is the chemical substance P?
  2. State whether P prefers to remains in the sunlit side of a stem or in shade.
  3. What is the effect of substance P on the rate of growth of (i) a root, and (ii) a stem?
  4. What is the name of process (i) Q, and (ii) R?
  5. What is the general name of chemical substances like P? Name another substance which belongs to this class of chemical substances.
Draw schematic of power plant based on natural gas and answer the following questions:
(a) At which place natural gas power plant is situated in Maharashtra?
(b) How is pollution reduced in natural gas based power plant?
(c) Give two examples of eco-friendly electricity process.