Q58 of 181 Page 306

An atom has the electron structure of 2, 7.

(a) What is the atomic number of this atoms?


(b) To which of the following would it be chemically similar?


7N, 15P, 17Cl, 18Ar


(c) Why would you expect it to be similar?

(a) The election structure is (2,7) so we have to add these electrons to get the atomic number. Therefore the atomic number is 9.

(b) Chlorine which has atomic number 17 is chemically similar.


(c) They expect to be similar because both have same number of valence electron 7.


More from this chapter

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56

Which of the following set of elements is written correctly in the order of their increasing metallic character?

 57

The atomic numbers of the three elements X, Y and Z are 2, 6 and 10 respectively.

(i) Which two elements belong to the same group?


(ii) Which two elements belongs to the same period?


Give reasons for your choice.

 59

Consider the following elements:

20Ca, 8O, 18Ar, 16S, 4Be, 2He


Which of the above elements would you expect to be:


(i) Very stable?


(ii) In group 2 of the periodic table?


(iii) In group 16 of the periodic table?

 60

In each of the following pairs, choose the atom having the bigger size:

(a) Mg (At. No. 12) or Cl( At. No. 17)


(b) Na (At. N0. 11) or K (At. No. 19)