miss話唔駛考呢d野呀,,thx咁多位.. 但係我想問 一條問題 .. 有particle X同Y X mass number係19, , atomic number係9 ,, proton有9,,electron有9,,neutron有10 Y mass number係19 ,, atomic numeber係9,,proton有9,,electron有10,,neutron有10 what is the relationship between X and Y ? 答案點解係Y is an anion of X 既 .. 個答案其實係點解 ?? |