structure of atom class 11 mcq

Isotopes have different physical properties due to 1) same number of protons 2) same number of electrons 3) same number of neutrons 4) Different number of neutrons or different mass numbers

Among the following which elements can show  multiple valencies 1) sulphur 2) phosphorus 3) sodium 4) both a, b

The isotope of iodine is used in the treatment of 1) cancer 2) goitre 3) age of fossil 4) fuel in nuclear react

The number of isotopes that are exhisted for both xenon and cesium are 1) 46 2) 16 3) 26 4) 36