In successive emission of -and -particles, the number of -and -particles should be emitted for the conversion of 92U238 to 82P206 are
An element xAy emits 5 α and 4β particles to give 82B207. The number of protons and neutrons in A are respectively
88, 227
88, 139
82, 227
84, 139
Which of the following travels with the speed of light?
α-rays
β-rays
γ-rays
X-rays
C.
γ-rays
Gamma (γ) rays travel with the speed of light because they have zero charge and zero mass.
90Th228 emits four alpha and one beta particles. Number of neutrons in daughter element is
129
190
232
138
Which of the ions is colourless inspite of the presence of unpaired electrons ?
La3+
Eu3+
Gd3+
Lu3+
Uncertainty in the position of an electron (mass= 9.1 x 10-31 kg) moving with a velocity 300 ms-1 accurate upon 0.001 % will be (h = 6.63 x 10-34 J-s)
19.2 x 10-2 m
5.76 x 10-2 m
1.92 x 10-2 m
3.84 x 10-2 m