This question refers to the elements of the periodic table with atomic numbers 3 to 18.
(a) (i) Which of them are noble gases?
(ii) Which of them are halogens?
(iii) Which of them are akali metals?
(iv) Which are the elements with valency 4?
(b) An element with atomic no. 3 combines with another element with atomic number 17; what would be the formula of the compound?
(c) What is the electronic configuration of an element with atomic number 10?
Answers
Explanation:
(a) i) gases with atomic number 10 and 18 which are Neon and Argon resp.
ii) gases with atomic number 9 and 17 which are Flourine and Chlorine resp.
iii) elements with atomic number 3 and 11 which are Lithium and Sodium resp.
iv) elements with atonic number 6 and 14 which are Carbon and Silicon resp.
(b) The formula of compound would be XY (LiCl).
(c) 2, 8
Periodic Table
Explanation:
(a)
(i) Elements of Group 18 are noble gases - Neon (Ne) with atomic number 10 and Argon (Ar) with atomic number 18.
(ii) Elements of Group 17 are halogens - Fluorine (F) with atomic number 9 and Chlorine (Cl) with atomic number 17.
(iii) Elements of Group 1 are alkali metals except hydrogen (H) - Lithium (Li) with atomic number 3 and Sodium (Na) with atomic number 11.
(iv) Elements with valency 4 are elements of Group 14 - Carbon (C) with atomic number 6 and Silicon (Si) with atomic number 14.
(b) Element with atomic number 3 is Lithium (Li). It has one valence electron, which it can lose to become stable.
Element with atomic number 17 is Chlorine (Cl). It has 7 valence electrons. Chlorine attracts one electron to become stable.
So the compound of Li and Cl would be LiCl (Lithium Chloride).
(c) The electronic configuration of element with atomic number 10 is Neon (Ne) - 2, 8, 8.