Alpha paicle has: September 2011: (A) 1 proton, 2 neutrons, (B) 1 proton, 1 neutron, (C) 2 protons, 1 neutron, (D) 2 protons, 2 neutrons
Answer is D. Ans. D: 2 protons, 2 neutrons Alpha paicles are simple helium nuclei (i.e. consisting of 2 protons and 2 neutrons) Remember: Alpha rays: Most ionizing Gamma rays: Maximum penetration power Cesium-137, cobalt and radium emits predominantly: Gamma rays