Periodic Classification

NCERT Exemplar Problems

MCQ 3

Question 19: What type of oxide would Eka– aluminium form?

1. EO₃
2. E₃O₂
3. E₂O₃
4. EO
   Answer: (c) E₂O₃

Question 20: Three elements B, Si and Ge are

1. Metals
2. Non-metals
3. Metalloids
4. Metal, non-metal and metalloid respectively
   Answer: (c) Metalloids

Question 21: Which of the following elements will form an acidic oxide?

1. An element with atomic number 7
2. An element with atomic number 3
3. An element with atomic number 12
4. An element with atomic number 19
   Answer: (a) An element with atomic number 7

Question 22: Which one of the following depicts the correct representation of atomic radius(r) of an atom?

1. (i) and (ii)
2. (ii) and (iii)
3. (iii) and (iv)
4. (i) and (iv)
   Answer: (b) (ii) and (iii)

Question 23: Which one of the following does not increase while moving down the group of the periodic table?

1. Atomic radius
2. Metallic character
3. Valence
4. Number of shells in an element
   Answer: (c) Valence

Question 24: On moving from left to right in a period in the periodic table, the size of the atom.

1. Increases
2. Decreases
3. does not change appreciably
4. first decreases and then increases
   Answer: (b) Decreases

Question 25: Which of the following set of elements is written in order of their increasing metallic character?

1. Be Mg Ca
2. Na Li K
3. Mg Al Si
4. C O N
   Answer: (a) Be Mg Ca

Question 26: The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following categories does the element belong?

1. Metal
2. Metalloid
3. Non-metal
4. Left-hand side element
   Answer: (b) Metalloid