Click here to know Alpha Particle mass (α). These interactions are with the loosely bound, outer electrons of the atoms in the material and should not be considered collisions. Visit CoolGyan to learn what is an alpha particle its charge, symbol, mass number, the general form for alpha decay and example. Class 12; Class 11; Class 10; Class 9; Class 8; Class 7; Class 6; Previous Year Papers. The best-known source of alpha particles is alpha decay of heavier (> 106 u atomic weight) atoms. Since the particle is positively charged, it exerts an attractive force on the oppositively charged electron.

The two neutrons of an alpha particle give it additional mass that further facilitates ionization by coulombic interaction or even direct collision of the alpha particle with atomic electrons. Study Material. The mass of an alpha particle is- Alpha particle mass is αm = 6.644657230 (82) × 10-27 Kg Terms within the parenthesis represent the error factor. The mass of an alpha particle is four atomic mass units, therefore the loss of an alpha particle decreases the parent nuclide's atomic mass number by four. An alpha particle can be called by interchangeable term doubly ionized helium nuclei (He 2+). NCERT Solutions. Alpha particle, positively charged particle, identical to the nucleus of the helium -4 atom, spontaneously emitted by some radioactive substances, consisting of two protons and two neutrons bound together, thus having a mass of four units and a positive charge of two. The atomic number of the atom goes down by exactly two, as a result of the loss of two protons – the atom becomes a new element. When an atom emits an alpha particle in alpha decay, the atom's mass number decreases by four due to the loss of the four nucleons in the alpha particle. The alpha particle has a high electrical charge but a low velocity due to its large mass, and interactions are frequent. Examples of this sort of nuclear transmutation are when uranium becomes thorium, or radium becomes radon gas, due to alpha decay.