(a) An element X is represented as (^{40}_{20} X)
(i) How many electrons and how many neutrons are present in the atom of X?
(ii) Write the electronic configuration of the atom
(b) Chlorine, whose atomic number is 17, reacts with the element X to form a compound.
(i) What type of bond is formed between X and chlorine?
(ii) Explain how the bond between X and chlorine is formed
(iii) Write the formula of the compound formed and statelhree properties of the compound.
(c) Chlorine has two isotopes of mass numbers 35 and 37 respectively. Suggest the possible relative molar masses of a chlorine molecule.
(d) Calculate the mass of one atom of carbon, given that one mole of carbon weighs 12.0g. (L = 6.02 x 10(^{23}))
Explanation
(a)(i) 20 electrons and 20 neutrons
(ii) 1s(_2), 2s(_2), 2p(_6), 3s(_2), 3p(_6), 4s(_2)
(b)(i) Ionic bond
(ii) Element X has valency electrons of 2 which it completely lost to two chlorine atoms which has valency electrons of 7 respectively. By the above event, each of the atoms involved in the bond completes its outermost octet electronic structure of stability as the noble elements. They then come together as aggregates of ions of opposite charges.
(iii) XCl(_2) : It dissolves in water. It can conduct electricity. It has high boiling point
(c) The relative molar mass of chlorine is 35.5
(d) 6.02 x 10(^{23}) atoms
C = 12.0g
1 atom C = (frac{12.}{6.02}) x 10(^{-23})
= 2.0 x 10(^{-23})g