If the radioactive decay constant of a radioactive substance is 0.00693 per year, what is the half-life of the substance?

(ln2 = 0.693)

If the radioactive decay constant of a radioactive substance is 0.00693 per year, what is the half-life of the substance?

(ln2 = 0.693)

The total decay rate R of a sample is related to the decay rate $$\text R_0$$​ at t = 0 and the disintegration constant or decay constant λ as:

A nucleus has an atomic number 64. Considering the nucleus as a liquid-drop, its radius will be close to

($$\text R_0$$​= 1.2 fm):

Let N and $$\text N_0$$​ be the number of radioactive nuclei in a sample at time t and at time t = 0, respectively. Then the ratio ($$\frac{\text N}{\text N_0}$$​) is equal to __________ where λ is the disintegration constant or decay constant.

The total energy released if 47 g of $$^{235}\text U$$​ undergoes fission (disintegration energy per event, Q = 200 MeV, Avogadro's number = 6.02 × $$10^{23}$$​ nuclei/mol) is close to:

A radioactive nucleus emits 3 alpha particles and 2 positrons. For the resultant nucleus, the ratio of neutrons to protons is (consider the initial nucleus to have atomic number Z and atomic mass A):

The half life of a radioactive substance is 10 years and its initial mass is 1 g. The remaining amount after 20 years is ________.

The source of energy in stars is:

Isotopes have the same number of:

When the masses of an electron, proton, and neutron are $$\text m_\text e,\text m_\text p$$​, and $$\text m_\text n$$​, respectively, then the nuclear mass of an atom $$_\text Z\text X^\text A$$​ is _________.