> A [subatomic](https://www.google.com/search?sca_esv=a0e199fc98d1a06b&sxsrf=ADLYWILAdU6xiFqAjfdoEIQmxTvDa3QOSQ:1715132349226&q=subatomic&si=ACC90nxMSPeZfdJJjQgDsdZJuFuJ3gUQFV0uT8hVxArDY0h0crGNALhmUK3vJ3MIkuIg6ZYf9oNPZmS4Vqyi_kuGrhWg3TbEJo1Okv_2DuMPvUgXUXAeeCw%3D&expnd=1&sa=X&sqi=2&ved=2ahUKEwj7jKzz9fyFAxVdJTQIHQZ9DBUQyecJegQIIBAO) particle of about the same mass as a [proton](https://www.google.com/search?sca_esv=a0e199fc98d1a06b&sxsrf=ADLYWILAdU6xiFqAjfdoEIQmxTvDa3QOSQ:1715132349226&q=proton&si=ACC90nwdkA2npcVVmNPViiSe8FMKC0ruq2C51FL2bpnuq4emXrETPn-fMbP2_-lN83PJfb-I8CnpTQJvLR8fkbI0MwYcahYstQ%3D%3D&expnd=1&sa=X&sqi=2&ved=2ahUKEwj7jKzz9fyFAxVdJTQIHQZ9DBUQyecJegQIIBAP) but without an [[Electricity|Electric]] charge, present in all atomic [nuclei](https://www.google.com/search?sca_esv=a0e199fc98d1a06b&sxsrf=ADLYWILAdU6xiFqAjfdoEIQmxTvDa3QOSQ:1715132349226&q=nuclei&si=ACC90nwdkA2npcVVmNPViiSe8FMKFmqZMaLVTRhhH7KYTwOrWT6LthpZ3Ar2WFkuTXpkpOvn90Csg7eec4jLrSdLF6nv64-0BA%3D%3D&expnd=1&sa=X&sqi=2&ved=2ahUKEwj7jKzz9fyFAxVdJTQIHQZ9DBUQyecJegQIIBAQ) except those of ordinary hydrogen
- has same mass as [[Protons|Proton]]