`K^(40),Ar^(40),Ca^(40)` are

._(8)(O)^(16) and ._(8)(O)^(18) are isotpes while ._(20)(Ca)^(40) and ._(18)(Ca)^(40) are isobars.

Which of the following pairs represent isotopes and which represent isobars? ""_(19)^(40)K, ""_(20 )^(40)Ca Calculate the difference in the number of neutrons in the isotopic pairs.

._(19)^(39)K and ._(20)^(40)Ca are

What is the minimum photon energy required to remove the least bound neutron of ._(20)^(40)Ca and ._(18)^(40)Ar . The nesessary atomic masses (in mu ) are given below: {:(M(.^(40)Ca)=39.962591 u),(M(.^(39)Ca)=38.970719 u),(M(.^(40)Ar)=39.962383 ),(M(.^(39)Ar)=38.964314 u),(" "m_n=1.008665 u):}