An isotone of 32Ge76 is:
(i) 32Ge77
(ii) 33As77
(iii) 34Se77
(iv) 34Se78
1. only (i) & (ii)
2. only (ii) & (iii)
3. only (ii) & (iv)
4. (ii) (iii) & (iv)
Which of the following has greater number of electrons than neutrons?
1. Al3+
2. O2-
3. F-
4. C
The work function of a metal is 4.2 eV. If radiations of 2000 fall on the metal then the kinetic energy of the fastest photoelectron is
1. 1.6 x 10-19J
2. 16 x 1010J
3. 3.2 x 10-19J
4. 6.4 x 10-10J
The relationship between energy E, of the radiation with a wavelength 8000 and the energy of the radiation with a wavelength 16000 is:
1. E1 = 6E2
2. E1 = 2E2
3. E1 = 4E2
4. E1 = 1/2E2
The transition of electrons in H atom that will emit maximum energy is:
1. n3 n2
2. n4 n3
3. n5 n4
4. n6 n5
The transition in the He+ ion in the balmer series that would have the same wave number as the first Lyman line in the hydrogen spectrum is-
1. | \(2 \rightarrow1\) | 2. | \(5 \rightarrow3\) |
3. | \(4 \rightarrow2\) | 4. | \(6 \rightarrow4\) |
If the speed of electron in Bohr's first orbit of hydrogen atom be x, then speed of the electron in 3rd orbit is:
1. x/9
2. x/3
3. 3x
4. 9x
In Bohr's model of the hydrogen atom the ratio between the period of revolution of an electron in the orbit n=1 to the period of revolution of the electron in the orbit n=2 is
1. 1:2
2. 2:1
3. 1:4
4. 1:8
A cricket ball of 0.5 kg is moving with a velocity of 100 ms-1. The wavelength associated with its motion is:
1. 1/100cm
2. 6.6 x 10-34m
3. 1.32 x 10-35m
4. 6.6 x 10-28m
The number of electrons in 19 K with quantum numbers n=3; l=0 is/are:
1. 2
2. 1
3. 4
4. 3