sat化学题Isotopes(同位素) of uranium have differenta.atomic numbersb.atomic massesc. d.想问下a为什么不对?答案是b

sat化学题Isotopes(同位素) of uranium have differenta.atomic numbersb.atomic massesc. d.想问下a为什么不对?答案是b SAT2化学题,关于同位素的All of the following carbon isotopes are radioactive EXCEPT(A) C10(B) C13(C) C14(D) C15(E) C16我靠,这可怎么判断呀!?要请教请教高手～（答案是B) The element europium exists in nature as two isotopes:151Eu hasa mass of 150.9196amu,and 153Eu has a mass of 151.96amu.Calculate the relative abundance of the two europium isotopes.请大虾们顺便说说isotopes(同位素)的用法（公式 用途 SAT2化学题One reason why certain isotopes have an unstable nucleus is because the number of A质子比中子多B电子比质子多C中子比电子多D质子比电子多E中子比质子多答案是英文的, 化学题 . 化学题.. 化学题. 化学题. SAT SAT Sat sat sat SAT SAT SAT SAT 请问一道高一下化学题,关于同位素的硼（B）有2种同位素,一种核内有5个中子,一种核内有6个中子.B的相对原子质量是10.8,则B的这两种同位素的原子个数比是多少?我刚学,还不是很会.