Nuclei

Because of large mass and large velocity, -particles have large ionising power. Each -particle produces thousands of ions before being absorbed. The -particles ionise the gas through which they pass, but their ionising power is only th that of -particles. -rays have got small ionising power.
Because of large mass, the penetrating power of -particles is very small, it being times that to -rays and times that of -rays. -particles can be easily stopped by an Aluminium sheet, only mm thick. -particles have very small mass, so their penetrating power is large. -rays have very large penetrating power.

Radiocarbon dating relies on a simple natural phenomenon. As the earth's upper is bombarded by cosmic radiation, atmospheric nitrogen is broken down into an unstable isotope of carbon-carbon . The unstable isotope is brought to earth by atmospheric activity, such as storms, and becomes fixed in the biosphere. Because it reacts identically to and attached to complex organic molecules through photosynthesis in plants and becomes their molecular makeup. Animals eating those plants in turn absorb carbon- 14 as welll as stable isotopes. This process of ingesting C- 14 continues as long as the plant or animal remains alive. The C-14 within an organism is continually decaying into stable carbon isotopes, but organism is absorbing more during its life, the ratio of to remains about same as the ratio in the atmosphere. When the organism dies, the ratio of C-14 within its carcass begins to gradually decrease.

Alpha particle has mass number and atomic number Therefore, after emission of an alpha particle. The mass number of the will reduce by and after decay it becomes

After half-lives the quantity of a radioactive substance left intact (undecayed) is given by Here, Equating the powers on both sides

The correct answer is C) The binding energy is the energy generated when a nucleus is built up from its component nucleons. As a result, the binding energy of the nucleus equals the energy equivalent of the mass defect. Because there are more protons in a heavier nucleus, the internal repulsive forces are stronger, and less energy is required to remove a nucleon from the nucleus, hence the binding energy is lower. As a result, the binding energy is greater for lighter nuclei. The more binding energy there is, the more stable the nucleus.

The correct option is B)
t =3.8 day
∴ λ = = = 0.182
If the initial number of atoms is a=A_0​ then after time t the number of atoms is = a


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