Chalcogens means ore forming, as most of the ores in the earth crust are either oxides or sulphides, group 16 elements are called chalcogens. for example: Oxygen is the most abundant of all the elements on earth. Oxygen forms about 46.6% by mass of earth’s crust.

Why are 16 groups called Chalcogens?

Chalcogens means ore forming, as most of the ores in the earth crust are either oxides or sulphides, group 16 elements are called chalcogens. for example: Oxygen is the most abundant of all the elements on earth. Oxygen forms about 46.6% by mass of earth’s crust.

Why is the third period contains 8 elements and not 18?

According to the 2n2 rule, the maximum number of electrons in the third period = 2 x (3)2 = 18. But, the last shell cannot accommodate more than 8 electrons so, the number of electrons in third period is 8. Hence, the number of elements is also 8.

Why lanthanides are called so?

They are called the lanthanides because they exhibit similar chemical properties to lanthanum, the first element in the group. Actinides are the 15 elements with atomic numbers from 89 to 103. They are named after the first element in the series, actinium.

What is the difference between actinides and lanthanides?

The lanthanide series includes elements 58 to 71, which fill their 4f sublevel progressively. The actinides are elements 89 to 103 and fill their 5f sublevel progressively. Actinides are typical metals and have properties of both the d-block and the f-block elements, but they are also radioactive.

What do you mean by actinides?

All actinides are radioactive and release energy upon radioactive decay; naturally occurring uranium and thorium, and synthetically produced plutonium are the most abundant actinides on Earth. These are used in nuclear reactors and nuclear weapons. The other actinides are purely synthetic elements.

Where are Chalcogens found?

The chalcogens, the oxygen group, is located in column 16 of the periodic table. It contains the elements oxygen, sulfur, selenium, tellurium, polonium, and ununhexium (O, S, Se, Te, Po, and Uuh, respectively).

What color are actinides?

Actinides ions in an aqueous solution are colorful, containing colors such as red purple (U3+), purple (Np3+), pink (Am3+), green (U4+), yellow green (Np4+), and pink red (Am4+).

What is the Colour of lanthanides?

Color and Light Absorbance

Ion Unpaired Electrons Color
Nd3+ 3 Reddish
Pm3+ 4 Pink; yellow
Sm3+ 5 Yellow
Eu3+ 6 Pale Pink

How do you find the electronic configuration?

To calculate an electron configuration, divide the periodic table into sections to represent the atomic orbitals, the regions where electrons are contained. Groups one and two are the s-block, three through 12 represent the d-block, 13 to 18 are the p-block and the two rows at the bottom are the f-block.

What is meant by electronic configuration?

Electronic configuration, also called electronic structure, the arrangement of electrons in energy levels around an atomic nucleus. In terms of a more refined, quantum-mechanical model, the K–Q shells are subdivided into a set of orbitals (see orbital), each of which can be occupied by no more than a pair of electrons.

What are actinides give three examples?

The Actinide series contains elements with atomic numbers 89 to 103 and is the third group in the periodic table. Actinium, Thorium, uranium curium are the some example of Actinides series.

Are lanthanides man made?

They are broken into two groups: the lanthanide series and the actinide series, also called trans-uranium, which means they are man-made.

Why are actinides Coloured?

Actinide cations are coloured? The colour is due to electronic transition within the 5f levels. The electronic transitions of actinides are about ten times more intense than those of lanthanides. The difference is due to difference in 4f and 5f electrons.

Why are lanthanides and actinides?

The reason why Lanthanides and Actinides are located at the bottom of the periodical table is because of their properties and in the block in which electrons fill up. The lanthanides include elements 58 to 71 (fill out the 4f subshell) and the actinides include elements 89 to 103 (fill out the 5f subshell).

What are the lanthanides and actinides called?

The lanthanides and actinides together are sometimes called the inner transition elements.

What are the characteristics of Chalcogens?

The Oxygen Family (Chalcogens)

  • Oxygen: colorless, tasteless, odorless, gas, melting point= 54.8 k, boiling point= 90.19 k.
  • Sulfur: pale yellow, brittle, tasteless, odorless, solid, melting point= 386 k, boiling point= 717.824 k.

What is the heaviest Chalcogen?


Why are there 14 lanthanides and actinides?

There are 14 lanthanides and actinides because the differentiating electron enters (n – 2)f subshell. Here the maximum capacity of f sunshell is 14 electrons. Therefore, there are only 14 lanthanides and 14 actinides.

What is Group 15 called?

Nitrogen group element, any of the chemical elements that constitute Group 15 (Va) of the periodic table. The group consists of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and moscovium (Mc).

What is the family name for Group 16?


Why are actinides unstable?

The radioactivity of the actinide elements is caused by their nuclear instability. In order to become more stable, the nucleus of an actinide element undergoes radioactive decay, releasing gamma rays, alpha particles, beta particles, or neutrons.

What are the properties of actinides?

Actinides share the following properties:

  • All are radioactive.
  • Actinides are highly electropositive.
  • The metals tarnish readily in air.
  • Actinides are very dense metals with distinctive structures.
  • They react with boiling water or dilute acid to release hydrogen gas.
  • Actinide metals tend to be fairly soft.

Why are they called Chalcogens?

The group VIA elements are called chalcogens because most ores of copper (Greek chalkos) are oxides or sulfides, and such ores contain traces of selenium and tellurium. Atomic properties of the chalcogens are summarized in the table.

What is the electronic configuration of 16?

Looking at the table we can say that the number of valence electrons of elements of chalcogen elements is 6. The symbol of elements written in the square bracket is the nearest noble gas elements. Now, we can say that the general electronic configuration of group 16 elements is ns2np4.

Who discovered lanthanides and actinides?


What do all Chalcogens have in common?

All chalcogens have six valence electrons. Most form -2 anions, but the oxidation states can vary. Chalcogens become more metallic as you go down the group. This group contains nonmetals, metalloids, and metals.

How do you learn lanthanides and actinides?

Mnemonic for Lanthanides Part 3: E re, dekh Tamatar Yellow aur bLue hain. Actinides include these f-block elements – Thorium (Th), Protactinium (Pa), Uranium (U), Neptunium (Np), Plutonium (Pu), Americium (Am), Curium (Cm), Berkelium (Bk), Fermium (Fm), Mendelevium (Md), Nobelium (No), and Lawrencium (Lr).

What is the use of actinides?

A large number of actinides are used for the defense operations, nuclear weapons and for the production of energy. Plutonium is used in nuclear reactors and for nuclear bombs as well. Many of the actinide elements are used in the nuclear power plant and also for the production of electronic power.