An unstable nucleus of an element decays by emitting an α-particle or a β⁻ particle to become a nucleus of a different element. This nucleus is also unstable and emits an α-particle or a β⁻ particle. The process continues until an isotope of the original element is produced. What is the minimum possible number of these particles emitted?

Which row describes the relative ionizing power and the relative penetration power per unit length in air of α-partic…

A nucleus of sodium-21, ²¹₁₁Na, decays to form a new nucleus containing 10 protons and 11 neutrons. Which leptons are…

A nucleus of bismuth-212 (²¹²Bi) decays by the emission of an α-particle and γ-radiation.

A skydiver, who is falling vertically through the air, opens his parachute. Which row describes the velocity of the s…

An egg of mass 25 g falls vertically downwards from the surface of a table which is 900 mm above the ground. Air resi…

Which expression is equal to the stress on a wire?