--%>
Assignment Help - homework help

Explanation of oxygen family.

Group 16 of periodic table contains five elements namely, oxygen (O), sulphur (S), selenium (Se), tellurium (Te) and polonium (Po). These are collectively known as chalcogens or ore forming elements because many metal ores occur as oxides and sulphides. These elements belong to p-block. The first four members of group 16 are non-metals. Polonium has metallic character and is a radioactive element with a very short period.

Oxygen, the most abundant element, is a vital element of atmosphere and ocean. It composes 46.6% of earth's crust. It forms about 21% of air as the free element and 89% of the ocean by weight. Sulphur is less abundant and occurs about 0.052% of the earth's crust. Sulphur is also referred as Brim stone. The name sulphur is derived from Sanskrit word 'Sulveri' which means 'killer of copper'. Compared to oxygen and sulphur the other members of this group are rare.

Atoms of these elements have outer electronic configuration as ns2np4, where n varies from 2 to 6. The electronic configurations of the elements of group 16 are shown in the table below:

Elements

At. No.

Electronic configuration

Abundance in earth's crust (ppm)

Oxygen (O)

8

[He] 2s2 2p4

4.66 × 105

Sulphur (S)

16

[Ne] 3s2 3p4

5.20 × 102

Selenium (Se)

34

[Ar] 3d10 4s2 4p4

9.0 × 10-2

Tellurium (Te)

52

[Kr] 4d10 5s2 5p4

2 × 10-3

Polonium (Po)

84

[Xe] 4f14 5d10 6s2 6p4

-


The four p-electrons of the outermost shell are arranged as px2 py1 pz1. Thus, there are two half-filled p-orbitals which are used for bonding with other elements. From the similar outer electronic configuration of these elements, it is expected that they will show similar physical and chemical properties.

Oxygen the first member of this group has very high ionization energy (1314 kJ mol-1) and differs markedly from other members of the family.

Oxygen, on the other hand, is found to exhibit remarkable resemblance with its neighbours, nitrogen and fluorine. For example, it forms strong pπ-pπ bond like nitrogen. Also it forms hydrogen bonds like nitrogen and fluorine.

   Related Questions in Chemistry

  • Q : Question related to colligative

    The colligative properties of a solution depend on: (a) Nature of solute particles present in it (b) Nature of solvent used (c) Number of solute particles present in it (d) Number of moles of solvent only

    		•
  • Q : Explain equilibrium and molecular

    The equilibrium constant can be treated as a particular type of molecular distribution. Consider the simplest gas-phase reaction, one in which molecules of A are converted to molecules of B. the reaction, described by the equation

    Q : Problem on reversible and irreversible

    The second law states that  dS ≥ (dQ/T), where dS = dQ/T for a reversible process and dS > dQ/T for an irreversible process.   a. Show that since dW12 = -dW21 (dWreverse = -dWforward) for a r

    		•
  • Q : What are ion selective electrodes? Ion

    Ion Selective Electrodes An ion selective membrane can be used to form an electrochemical cell whose emf depends on the concentration of that ion. Before we proceed to an important application of emf measurements, brie

    		•
  • Q : Analytical chemistry 37% weight of HCl

    37% weight of HCl and density is 1.1g/ml. find molarity of HCl

    		•
  • Q : Explain reactions of carbonyl oxygen

    In these reaction oxygen atom of carbonyl group is replaced by either one divalent group or two monovalent groups. Reaction by ammonia derivatives: aldehydes and ketones react with a number of ammonia derivatives such as hydroxylaminem hydrazine, semicarbazide etc. in weak acidic medium.

    		•
  • Q : Simulate the column in HYSYS The

    The objective of this work is to separate a binary mixture and to cool down the bottom product for storage. (Check table below to see which mixture you are asked to study). 100 kmol of feed containing 10 mol percent of the lighter component enters a continuous distillation column at the m

    		•
  • Q : Question based on maximum vapour

    Provide solution of this question. Which has maximum vapour pressure: (a) HI (b) HBr (c) HCl (d) HF

    		•
  • Q : Direction of dipole moment expected

    Illustrate the direction of the dipole moment expected for hydrogen bromide?

    		•
  • Q : Atmospheric pressure Give me answer of

    Give me answer of this question. The atmospheric pressure is sum of the: (a) Pressure of the biomolecules (b) Vapour pressure of atmospheric constituents (c) Vapour pressure of chemicals and vapour pressure of volatile (d) Pressure created on to atmospheric molecules

    		•