(A) the total energy of an electron revolving in any stationary orbit is negative. (R) energy can have positive or negative values.

Monjur Alahi

(A) the total energy of an electron revolving in any stationary orbit is negative.
(R) energy can have positive or negative values.
A. if both assertion and reason are true and reason is the correct explanation of assertion.
B. if both assertion and reason are true but reason is not the correct explanation of assertion.
C. if assertion is true but reason is false.
D. if both assertion and reason are false.


0 like 0 dislike
3 views
Share with your friends

1 Answers

Salim Ahmed Kawsar

Call

Correct Answer - B
Energy can have positive or negative values. in the atom. the electrons are bound . The negative energy of the revolving electrons does not allow the electrons to leave the atom. That the electrons are bound within the atom is indicated by energy being negative.

0 like 0 dislike
1 views
Talk Doctor Online in Bissoy App
An electron of a hydrogen like atom is in excited, state. If total energy of the electron is -4.6 eV, then evaluate (i) the kinetic energy and (ii) th

Given ,total energy of the electron `E=-4.6 EV` (i) Kinetic energy of electron K=-(Total energy E,) `rArr " " =-E=-(-4.6)=4.6 eV` (ii) de- Brogile wavelength `lambda_(d)=(h)/(sqrt(2 mK))=(6.6xx10^(-34))/(sqrt(2xx9.1xx10^(-31)xx4.6xx1.6xx10^(-19)))` `0.57xx10^(-9)m=0.57 nm`

2 Answers 2 views
In the nth orbit, the energy of an electron `E_(n)= -( 13.6)/(n^(2)) eV` for hydrogen atom. The energy rquired to take the electron from first orbit t

Correct Answer - A For n=2, using, `E_(n)=(-13.6eV)/(n^(2))E_(2)=-(13.6)/((2)^(2))=-3.4 eV` For n=1,`E_(1)=-13.6 eV` `:. " " E_(1rarr2)=-3.4-(-13.6)=10.2ev`

2 Answers 1 views
The velocity of an electron in the first orbit of H-atom is v. The velocity of an electron in the 2nd orbit

Correct Answer - C `vprop(Z)/(n)` since Z and n both have become twice, velocity of electron in second orbit of `H^(+)` will be v.

2 Answers 1 views
Electrons are revolving around the nucleus in `n_(1^(th))` orbit of an atom, have atomic number `Z_1`, and in the `n_2` orbit of other atom, have atom

Correct Answer - A,B,D `L_1/L_2=(mv_1r_1)/(mv_2r_2)=(Z_1/n_1xxn_1^2/Z_1)/(Z_2/n_2xxn_2^2/Z_2)=n_1/n_2implies P_1/P_2(mv_1)/(mv_2)=(Z_1/n_1)/(Z_2/n_2)=(Z_1n_2)/(Z_2n_1)` `(f_1)/(f_2) =(v_1/(2pir_1))/(v_2/(2pir_2))=(Z_1/n_1xxZ_1/n_1^2)/(Z_2/n_2xxZ_2/n_2^2)=(Z_1/Z_2)^2.(n_2/n_1)^3implies (K.E._1)/(K.E._2)=(1/2mv_1^2)/(1/2mv_2^2)=(Z_1/Z_2)^2xx(n_2/n_1)^2=((Z_1n_2)/(Z_2n_1))^2` `(K.E_1)/(K.E_2)=(1/2(KZ_1e^2)/r_1)/(1/2(KZ_2e^2)/r_2)=(Z_1/n_1^2.Z_1)/(Z_2.Z_2/n_2^2)=(Z_1/Z_2.n_2/n_1)^2`

2 Answers 1 views
The relation between the orbit radius and the electron velocity for a dynamically stable orbit in a hydrogen atom is (where, all notations have their

Correct Answer - C In hydrogen atom electrostatic force of attraction `(F_e)` between the revolving electrons and the nucleus provides the requisite centripetal force `(F_c)` to keep them in their orbits....

2 Answers 1 views
Total energy of electron in nth stationary orbit of hydrogen atom is

Correct Answer - C The kinetic energy of the electron in hydrogen atom are `K=(1)/(2)mv^2=(e^2)/(8piepsilon_0r)[becausev^2=(e^2)/(4piepsilon_0mr)]` electrostatic potential energy, `U=(-e^2)/(4piepsilon_0r)` The total energy E of the electron in a hydrogen atom is...

2 Answers 1 views
if an electron is revolving in its bohr orbit having bohr radius of `0.529Å`, then the radius of third orbit is

Correct Answer - C As`r_n=n^2a_0`, Here, `a_0=0.529Å` and `n=3` `therefore r_(n=3)=(3)^2a_0=9xx0.529Å=4.761Å`

2 Answers 1 views
An electron is revolving in the `n^(th)` orbit of radius `4.2 Å`, then the value of n is `(r-1=0.529 Å)`

Correct Answer - D Since `r_npropn^(2),(r_n)/(r_1)=(n^2)/((1)^2)` `therefore r_n=n^2r_1`or `n^2=(r_n)/(r_1)` `rArrn=sqrt((r_n)/(r_1))=sqrt((4.2)/(0.529))=sqrt(7.939)=2.81approx3`.

2 Answers 1 views
`.^(40)K` is an unusual isotope, in that it decays by negative beta emission, positive beta emission, and electron capture. Find the Q values for thes

The process for negative beta decay is given by equation `._(19)^(40)K_(21) rarr ._(20)^(40)Ca_(20) +e^(-) + barv` and the Q value is found from equation using atomic masses : `Q_(beta) [m(.^(40)K)...

2 Answers 1 views
If velocity of an electron in `I` orbit of `H` atom is `V`, what will be the velocity of electron in `3^(rd)` orbit of `Li^(2+)`

Correct Answer - A `V=2.188xx10^(6) Z/n m//s` Now, `V prop Z/n` so, `V_(Li^(2+))/V_(H)=-(Z_(1)//n_(1))/(Z_(2)//n_(2))=(3//3)/(1//1)=1` or, `V_(Li^(2+))=V_(H)`

2 Answers 1 views
X