You are here
Aman was discussing the structure of atom with his classmates. During the discussion, he learnt that an element X has a mass number of 35 and contains 18 neutrons. Based on this information, answer the following questions: (i) How many electrons and protons does element X have? (ii) What is its atomic number? (iii) Identify the element X. (iv) Write its electronic configuration. (v) How many valence electrons does it have? (vi) What will be the mass number if two neutrons are added to its nucleus? (vii) What will be the relation of X with the new atom?
View Answer
- (i) Protons = A − neutrons = 35 − 18 = 17; electrons = 17 .
- (ii) Atomic number = 17 .
- (iii) Element X = Chlorine (Cl) .
- (iv) Electronic configuration = 2, 8, 7 .
- (v) Valence electrons = 7 .
- (vi) New mass number (2 neutrons added) = 35 + 2 = 37 .
- (vii) X and the new atom have the same Z but different A → they are isotopes .
