Isotope

http://micro.magnet.fsu.edu/electromag/java/rutherford/

http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/ruther14.swf

Element	Symbol	Nuclear data
		Atomic Number	Mass number	Number of protons	Number of neutrons
Hydrogen	11H	1	1	1	0
Hydrogen	21H	1	2	1	1
Helium	32He	2	3	2	1
Helium	42He	2	4	2	2
Carbon	126C	6	12	6	6
Carbon	136C	6	13	6	7
Carbon	146C	6	14	6	8
Krypton	8336Kr	36	83	36	47
Krypton	8436Kr	36	84	36	48
Krypton	8636Kr	36	86	36	50
Radium	22388Ra	88	223	88	135
Radium	22688Ra	88	226	88	138
Thorium	22890Th	90	228	90	138
Thorium	23390Th	90	233	90	143
Uranium	23592U	92	235	92	143
Uranium	23692U	92	236	92	144
Uranium	23892U	92	238	92	146