Question

Circle the correct statement regarding the electronic structure of atoms:

(a) Electrons are described by wavefunctions. The electronic structure of an atom is uniquely specified by assigning four quantum numbers to each electron.

(b) The structure of an atom is best described as a solid sphere in which the electrons are embedded at different distances from the center. Outer shell electrons are found on the surface of the sphere.

(c) Electrons are the result of the superposition and interference of electro-magnetic waves of high intensity localized around the atomic nucleus.

(d) Electrons move in circular orbits around the nucleus similar to the planets around the sun. Electrons with higher principal quantum number orbit at longer distances from the nucleus.

2. Circle the correct statement regarding the meaning and use of enthalpy in thermochemistry:

(a) Enthalpy is another name for internal energy.

(b) Enthalpy is the particular form of work produced or absorbed by a chemical reaction.

(c) The change in enthalpy describes the heat released or absorbed by a chemical reaction at constant pressure when no work other than pressure-volume work is involved.

(d) The enthalpy is the sum of the heat and work produced or absorbed by a reaction at constant pressure for any kind of work, including pressure-volume work.

Answer 1

Ans 1 :d) Electrons move in circular orbits around the nucleus similar to the planets around the sun. Electrons with higher principal quantum number orbit at longer distances from the nucleus.

The atomic model of the element is considered similar to that of solar system wherein the negatively charged electrons revolve around the positively charged nucleus in fixed orbits.

The locations of these electrons in the atom are given by the set of 4 quantum numbers namely , principal , azimuthal , magnetic and magnetic spin quantum numbers.