Duduli

“Isoelectronic molecular species (I.e species having same number of atoms and same number of total valence electrons) have similar molecular orbitals and similar molecular structure.”

It is defined as the number of covalent bonds in a molecule.Bond order is equal to one half of the difference between the number of electrons in the bonding (Nb) and anti-bonding (Na) molecular orbitals.   I.e Bond order =1/2 (Nb-Na)

Answer:- It is the unit of solid angle and is defined as the solid angle subtended, at the centre, by a unit area of the surface of unit radius.

Answer:- These are the waves having longest wave-length(of the order of 10⁶cm) existing on a.c. power lines.In homes we get a.c. power supply at 50Hz. Most  of the energy is confined to power line, very little is radiated into space.

Answer:- Waves belonging to this region are visible to human eye and possess wave-lengths lying in between 3.9×10^-⁵cm and 7.8 × 10^-⁵cm.These waves are emitted by incandescent bodies and are capable of effecting photographic plates.

Answer:- It is the molecular weight of a substance expressed in grams or it is the weight in grams which is numerically equal to its molecular weight.It is also called gram molecule or simply one mole of a substance.

Answer:- It states that “the product of atomic weight and specific heat of an element is approximately equal to 6.4.” Mathematically,      Atomic weight × Specific heat = 6.4

Answer:- It is the average relative weight of an atom of an element as compared to the weight of carbon taken as 12. It has no units. However, it is expressed in a.m.u. which only signifies that it is taken on atomic mass unit scale.

Answer:- It is the impedance offered by a string to transverse, progressive waves and its defined as the ratio of transverse force to the transverse velocity.

Answer:- The resilience of an elastic body is its capacity to withstand a mechanical shock or a sudden blow without acquiring a permanent set.It is measured by the work done in subjecting the body to a strain within the elastic limit.

Answer:- The square of time period is proportional to the cube of the semi-major axis of its orbit.This is known as the harmonic law and gives the relationship between the size of the orbit of a planet and its time of revolution.

Answer:- The radius, drawn from the sun to a planet, sweeps equal areas in equal interval of time, i.e its areal velocity is constant.This is referred to as the law of areas and gives the relationship between the orbital speed  of the planet and its distance from sun.

Answer: The moments of inertia of certain bodies of a regular geometrical shape about any one of their three perpendicular axes of symmetry, passing through their centres of mass may, however, be directly obtained by directly obtained by the application of what is known as Routh's rule.

Answer:- A particle may be said to execute a simple harmonic motion if its acceleration is proportional to its displacement from its equilibrium position, or any other fixed point in its path, and is always directed towards it.

Answer:- The search for fundamental or absolute frame of reference resulted in the discovery, or rather than the invention of a medium called luminiferous ether or oftenly known as ether.

Answer:- The reference frame in which one body is initially at rest and other body approaches it so that collision takes place is called laboratory frame of reference.

Answer:- Elements present in the second and third periods show diagonal relationship with each other, i.e, they resemble each other.For example, Li, Be and B resemble Mg, Al and Si respectively.

Answer:- This is applicable to the identical, indistinguishable particles of zero integral spin.These particles are called bosons.The examples of bosons are helium atoms at low temperature and the photons.

Answer:- It is the property by virtue of which an element may exist in two or more forms which have different physical properties but almost similar chemical properties.

Answer:- This is applicable to the identical, indistinguishable particles of half integral spin.These particles obey Pauli exclusion principle and are called fermions.The examples of fermions are electrons, protons,neutrons etc.