A nucleus nXm emits one α and two β - particles. The resulting nucleus is.
nXm-4
n-2Ym-4
n-4Zm-4
None of these
Curie is a unit of
Energy of gamma rays
Half - life
Radioactivity
Intensity of gamma rays
The Bohr model of atoms :
Assumes that the angular momentum of electrons is quantized
Uses Einstein’s photoelectric equation
Predicts the same emission spectra for of atoms
Predicts the same emission spectra for all types of atoms
In any fission process the ratio
less than 1
greater than 1
equal than 1
Depends on the mass of parent nucleus
Energy released in the fission of a single 92U235 nucleus is 200 MeV. The fission rate of a 92U235 filled reactor operating at a power level of 5 W is.
1.56 × 10-10 s-1
1.56 × 10-11 s-1
1.56 × 10-16 s-1
1.56 × 10-17 s-1
A sample of radioactive element has a mass of 10 g at an instant t = 0. Calculate the approximate mass of this element in the sample after two mean lives ?
3. 70 g
6 . 30 g
1 . 35 g
2. 50 gs
If an a nuclear fusion process, the masses of the fusing nucle be m1 and m2 and the mass of the resultant nucleus be m3, then :
m3 = m1 + m2
m3 = | m1 - m2|
m3 < (m1 + m2)
m3 > (m1 + m2)
The stable nucleus that has a radius half that of Fe56 is
Li7
Na21
S16
Ca40
Alpha particles are
2 free protons
helium atoms
singly ionised helium atoms
doubly ionised helium atoms
In the nucleus of 11Na23, the number of protons, neutrons and electrons are.
11,12,0
23,12,11
12,11,0
23,11,12
