Q25 of 30 Page 196

The positions of three elements A, B and C in the periodic table are indicated below:


(a) State whether element C would be a metal or a non-metal. Why?


(b) Which is the more active element, A or C? Why?


(c) Which type of ion (cation or anion) will be formed by the element C? Why?

(a) Element C is non-metal because it belongs to 17 group and it contains 7 valence electrons so it can gain only one electron. So it is non-metal.


(b) In non-metals, electronegativity increases from left to right in a period due to increase in effective nuclear charge and decreases from top to bottom in a group due to increment in size. So A is the most active element.


(c) Since C is non-metal and it has 7 valence electrons. So it can gain only one electron and anion will be formed.


More from this chapter

All 30 →
23

The position of certain elements in the Periodic Table are shown below.


Using the above table answer the following questions:


(a) Which element will form only covalent compounds?


(b) Which element is a non-metal with valency 2?


(c) Which element is a metal with valency 2?


(d) Out of H, C, F, which has largest atomic size?


(e) Give name of family to which H, C and F belong?

 24

An element has electronic configuration 2, 8, 7.

(a) To which group and period of the long form of Periodic Table does it belong?


(b) What is atomic number of this element?


(c) Is it metallic or non-metallic and why?


(d) Identify the element.


(e) Name an element chemically similar to this element.

 26

Atoms of seven elements A, B, C, D, E, F and g have a different number of electronic shells but have the same number of electrons in their outermost shells. The elements A and C combine with chlorine to form and acid and common salt respectively. The oxide of element A is liquid at room temperature and is a neutral substance, while the oxide of the remaining six elements are basic in nature. Based on the above information, answer the following question:

(i) What could the element A be?


(ii) Will element A to G belong to the same period or same group of the periodic table?


(iii) Write the formula of the compound formed by the reaction of the element A with oxygen.


(iv) Show the formation of the compound by a combination of element C with chlorine with the help of electronic structure.


(v) What would be the ratio of number of combining atoms in a compound formed by the combination of element A with carbon?


(vi) Which one of the given elements is likely to have the smallest atomic radius?

 27

In the following table, six elements A, B, C, D, E and F (here letters are not the usual symbols of the elements) of the modern Periodic Table with atomic numbers 3 to 18 are given:


(a) Which of these is (i) a noble gas, (ii) a halogen?


(b) If B combines with F, what would be the formula of the compound formed?


(c) Write the electronic configurations of C and E.