Question

5. The F e, Na and Mg2 hve the same number of le Electron . Which of the following Matements about the top of a given element is correct The atom Nave the same number of protons but Tering number of rond b. The storms have the same number of neutron but rering number of electron C. The have the n umber of electrons but differing number of protons d. The Mons have the same number of neutrons but differing number of protons The atoms have the same number of protons but offering number of electron 47. How many electrons does the one have 1. 26 d. 51 48. An ion with a charge of minus three and the electronic configuration of krypton is a a. Gamion C. Bromide on o suride ion Arsenide on e Scandiam lon 4. The maximum number of electrons that can occupy a ingle orbital 50. All of the following are allowed energy levels except c. d. 3d Sp 51. The number of orbitals in an tSublevel is e 132 2033 52. The electron configuration of Alonis AF S10 122p 2p 3p b. 122p3s 3p Al->2e d. 22033 53. An Fe atom would be expected to have paired electrons 54. The number of unpaired electrons in an atom of arsenic is? 55. Atoms with the high first longation energies always have a. Large atomic radili d. e Positive ions with a high charge Tightly bound Valence electrons C. Low attraction for valence electrons 56. Which of the following processes represents the lonization energy of bromine? a l - Br + Bril) Brige b. B - Brille a Brig Br . e. Brigi e Bri) 57. Which of the following elements has the smallest first ionization energy? d. Mg 58. Which of the following has the highest this location energy? a. Mg AL d. CI 59. The elements in which of the following sequences have most nearly the same atomic radius? Ms. Al SIP c. Li, Na, K, Rb b. F, CI, Br, d. 0. 5. CI, AT (6) Mio, Tc, Ra, Wh 50. The correct order for decreasing atomic radius of the five atoms: Cs, Ba, C1, Brand is a. BrCbCB b. Bast-Brat -Ba-bbc

Answer 1

45. Electrons

All given species F^-, Ne, Na⁺, Mg⁺² contain 10 electrons.

The fluorine (Z=9) has one more electron than in its elemental structure and is represented by the minus charge. It indicates fluorine acquired one electron and converted into fluoride ion having 10 electrons. F^- = 9+1 = 10 electrons.

Neon, the stable noble gas has 10 electrons as its atomic number (Z) is 10. Ne = 10 electrons.

Sodium (Z=11) lost one electron to get stable noble gas configuration. Na⁺ = 11-1 = 10 electrons.

Magnesium (Z=12) lost two electrons to get noble gas configuration. Mg⁺² = 12-2 = 10 electrons.

46. A. Atoms having same number of protons but different number of neutrons in their nuclei are called isotopes.

There are different forms of elements available on earth. One of the different forms of a single element are isotopes. Every atom contains nucleus. Nuclei of every element contains neutrons and protons(except hydrogen atom). Those atoms which are having similar number of protons but different number of neutrons in their nuclei are isotopes to each other.

47. 29

The atomic number (Z) of the Iron atom is 26. It is also given in the atom mentioned (Left down to Fe). It means the elemental form of iron contains 26 electrons. The negative charge on the top of the atom (Fe^-3) indicates it is reduced which means it acquired three electrons. Thus 26+3 = 29 electrons. This Fe^-3 (ferric ion) contains 29 electrons.

48. Arsenide ion (As^-3)

Given that the ion contains the electronic configuration of Krypton (Kr, Z=36). It is also given that the ion has a charge of three minus which means the atom gain three electron to attain electronic configuration of Kr. This indicates the elemental atom which zero charge contains 36-3 = 33 electrons. 33 is the atomic number of Arsenic. Hence the required ion is arsenide ion.

49. 2

The maximum number of electrons an orbital can occupy is 2. These two electrons must have opposite spins. One rotates in a clockwise orientation and another anti-clockwise direction. Both spins cancel each other and stabilize in the orbital. Eg, P_x, P_y and P_z orbitals can accommodate 2 electrons each.

If this is the case like s,p,d,f orbitals, the maximum number of electrons an orbital can occupy are 14 in the 'f' orbital. As 14 is not given in options, the correct answer is 2.