Description : Tell what would happen to the stability of an atom, with atomic number higher than18, if the aufbau principle was not introduced.
Last Answer : Ans. We cannot find out the exact reason of stability of an atom & why they should have filled inner orbits before outermost shell.
Description : Explain why half-filled orbitals have extra stability.
Last Answer : Ans. It has symmetrical electron density as well as greater exchange energy.
Description : “In reality all the s-orbitals are spherically symmetric.” What does this represent?
Last Answer : Ans. The probable density of an electron in s-orbital is equally distributed at all coordinates in space.
Description : What accounts for the stability of an electron in multi-electron atom?
Last Answer : Ans. i.The angular momentum of an electron is integral multiple of h/2ח ii. The symmetrical electron density of an orbit. iii.The maximum transition energy of an orbital.
Description : How many maximum 3s electrons can have magnetic spin quantum number -1/2?
Last Answer : Ans. 1 electrons.
Description : What do you mean by Pauli’e exclusive principle? What is its significance?
Last Answer : Ans No two electrons will have same set of all q.no. If n,l,m are same i.e. same orbital ‘s’ will be differ. It shows that all electrons have a definite place in an atom or their own identity.
Description : Define Pauli’s exclusion principle ?
Last Answer : Ans. No two electrons in an atom can have same set ofall four quantum numbers. If three are same one Quantum number must have different value.
Description : State Heisenberg Uncertainty Principle.
Last Answer : Ans. It is impossible to determine the exact position & exact momentum or velocity of microscopic particle.
Description : What are different types of quantum numbers , write them with their symbols ?
Last Answer : Ans. 1.Principal Quantum Numbers (n) 2.Azimuthal Quantum Numbers(l) 3.Magnetic Quantum Numbers (m) 4.Spin Quantum Numbers(s)
Description : What is Hund’s rule of maximum multiplicity? What is its significance?
Last Answer : Ans Pairing of electrons in an orbital takes place only when all orbitals of same sub-shell become singly occupied. It helps to equalize energy of a sub-shell
Description : Explain the significance of spin quantum number.
Last Answer : Ans.The direction of spinning of an electron in an orbit as well as the net magnetic moment of an orbital.
Description : How many of the following are possible: 1p, 2s, 3p, 3f, 3d.
Last Answer : Ans.2s , 3p & 3d are possible.
Description : Explain the significance of Azimuthal quantum number.
Last Answer : Ans. It refers as sub-energy level of an atom.
Description : How many quantum numbers are needed to designate an orbital?
Last Answer : Ans.Three quantum numbers.
Description : Is the energy of an electron in 2s orbital same as of that in 2p orbital? Why?
Last Answer : Ans. No, the energy depends upon (n+l) values in an atom. Hence 2p orbital has greater energy than 2s.
Description : Why is s-orbital orbital considered non directional while p-orbital directional?
Last Answer : Ans. Electron density in s-orbital is equal in all direction while it dumble shaped along one axis in p- orbitals.
Description : Find the number of radial and angular nodes in 3d subshell?
Last Answer : Ans. Zero-angular node as well as radial nodes.
Description : Give the points of Rutherford Model.
Last Answer : Ans. 1. Atom is neutral. 2.Whole mass is concentrated in nucleus. 3.Electrons are revolving in orbits.
Description : Write two properties which cannot be explain by wave nature of radiation
Last Answer : Ans. 1.Photo electric effect 2. Black Body radiation
Description : Write the draw back of Rutherford Atomic Model.
Last Answer : Ans (1). He was unable to explain the stability of Atom. (2). He could not explain the line spectrum.
Description : Why; e/m value is not constant for canal rays ?
Last Answer : Ans. Mass of particles of cathode rays is not constant.
Description : What is threshold frequency?
Last Answer : Ans –The minimum frequency required to eject out electron from an atom.
Description : Name the spectral series which appear in the region of electromagnetic spectrum. (a) Visible region (b) UV region (c) Far IR region
Last Answer : Ans: (a) Balmer Series (b) Lymen Series (c) Pfund Series
Description : What is the difference between Quantum and photon?
Last Answer : Ans. The smallest packet of Energy of any radiation is called as Quantum and that of Light is known as Photon.
Description : Where are the two lone pairs of electrons of the oxygen atom in an alcohol molecule located? (a) in two p orbitals (b) in two sp orbitals (c) in two sp2 orbitals (d) in two sp3 orbitals
Last Answer : in two sp3 orbitals
Description : The number of electrons of a neutral atom is automatically known if one knows the? A. Atomic number (Answer) B. Atomic weight C. Number of orbitals D. none
Last Answer : A. Atomic number (Answer)
Description : In an atom the order of filling up of the orbitals is governed by which principle? -General Knowledge
Last Answer : The answer is 'Aufbau principle'
Last Answer : answer:
Description : In an atom the order of filling up of the orbitals is governed by which principle?
Last Answer : Aufbau principle
Description : “All the four quantum numbers of two electrons in an atom are not the same.” It is the law of — (1) Hund’s (2) Exclusion Principle of Pauli (3) Uncertainty Principle of Hiesenberg (4) Avogadro’s Law
Last Answer : Exclusion Principle of Pauli
Description : The high reactivity of fluorine is due to (1) small size of fluorine atom (2) its high electro negativity (3) availability of d-orbitals (4) strong F - F bond
Last Answer : (2) its high electro negativity Explanation: The high reactivity of fluorine is due to its high electro negativity.
Description : For which molecule can the bonding be described in terms of sp3 hybrid orbitals of the central atom? w) CH4 x) SF6 y) BF3 z) PCL5
Last Answer : ANSWER: B -- CH4
Description : Which of the following statements is correct regarding nucleophiles? (a) They have an overall positive charge (b) They have a lone-pair of electrons (c) They have an unpaired electron (d) They have empty orbitals
Last Answer : (b) They have a lone-pair of electrons
Description : The nuclei of heavy atoms generally contain: w) more electrons than neutrons x) more protons than electrons y) more neutrons than electrons z) more orbitals than electrons
Last Answer : ANSWER: Y -- MORE NEUTRONS THAN ELECTRONS
Description : In the filling of electron orbitals for the elemen sulfur, which has 16 electrons, the number of electrons in the 3p orbitals is: w) 3 x) 4 y) 6 z) 0
Last Answer : ANSWER: X -- 4
Description : Which principle is followed in the distribution of electrons in an atom?
Last Answer : Which principle is followed in the distribution of electrons in an atom?
Description : In which of the following central atom makes use of `sp^(3)` hybrid orbitals
Last Answer : In which of the following central atom makes use of `sp^(3)` hybrid orbitals A. `SO_(2)` B. `SO_(3)` C. `H_(2)S` D. `H_(2)O`
Description : The high reactivity of fluorine is due to (a) Its high electronegativity (b) Small size of flourine atom (c) Availability of d-orbitals (d) Strong F-F bond
Last Answer : Ans:(a)
Description : Which of the following contain maximum number of electrons in the antibonding molecular orbitals
Last Answer : Which of the following contain maximum number of electrons in the antibonding molecular orbitals A. `O_(2)^(2-)` B. `O_ ... O_(2)^(-1)` D. `O_(2)^(+)`
Description : Which of the following complex ions has electrons that are symmetrically filled in both `t_(2g) and e_(g)` orbitals ?
Last Answer : Which of the following complex ions has electrons that are symmetrically filled in both `t_(2g) and e_(g)` orbitals ? A ... D. `[Co(NH_(3))_(6)]^(2+)`
Description : The pair of electrons in the given carbanion, `CH_(3)C-=C^(Theta)` is present in which of the following orbitals?
Last Answer : The pair of electrons in the given carbanion, `CH_(3)C-=C^(Theta)` is present in which of the following orbitals? A. ... ` B. `sp^(2)` C. `2p` D. `sp`
Description : Among noble gases, Xe is quite reactive and form a number of fluorides and oxyfluorides. In these compounds the electrons, from 5p orbitals are excite
Last Answer : Among noble gases, Xe is quite reactive and form a number of fluorides and oxyfluorides. In these ... B. Square pyramid C. square planar D. octahedral
Last Answer : Among noble gases, Xe is quite reactive and form a number of fluorides and oxyfluorides. In these compounds ... `XeF_(2)` and tetraheddral `XeO_(3)`
Last Answer : Among noble gases, Xe is quite reactive and form a number of fluorides and oxyfluorides. In these compounds the ... ` C. `XeO_(2)F_(2)` D. Xe
Description : For principle quantum number `n = 4`, the total number of orbitals having `l =3` is
Last Answer : For principle quantum number `n = 4`, the total number of orbitals having `l =3` is A. 3 B. 7 C. 5 D. 9
Description : (3) the number of electrons orbiting around the nucleus Explanation: The chemical behavior of an atom is determined by the number of electrons on its outer shell. As for the chemical bonding properties of ... , and in what ratio atoms will bond to form the 20,000,000 different substances on Earth.
Last Answer : Methyl phenyl ether can be obtained by reacting - (1) phenolate ions and methyl iodide (2) methoxide ions and bromobenzene (3) methanol and phenol (4) bromobenzene and methyl bromide
Description : (1) they contain free electrons Explanation: Metals typically consist of closepacked atoms, meaning that the atoms are arranged like closely packed spheres. Two packing motifs are common, one ... surrounded by six neighboring atoms. Several metals adopt both structures, depending on the temperature.
Last Answer : Helium gas is filled in ballons because (1) its atomic number is 2 (2) it is lighter than air (3) it is one of the constitutents of water (4) it is a noble gas
Description : An atom of an element with mass number 23 and atomic number 11 will have- (1) 11 neutrons, 12 protons and 11 electrons (2) 11 protons, 12 neutrons and 11 electrons (3) 11 protons, 12 electrons and 11 neutrons (4) 23 protons and 11 electrons
Last Answer : (2) 11 protons, 12 neutrons and 11 electrons
Description : Chlorine atom and chloride ions - (1) Have an equal number of protons (2) Have an equal number of electrons (3) Unequal number neutrons (4) reacts spontaneously with water
Last Answer : (1) Have an equal number of protons