NCERT Exemplar Problems
Question 19: What type of oxide would Eka– aluminium form?
Answer: (c) E2O3
Question 20: Three elements B, Si and Ge are
- Metal, non-metal and metalloid respectively
Answer: (c) Metalloids
Question 21: Which of the following elements will form an acidic oxide?
- An element with atomic number 7
- An element with atomic number 3
- An element with atomic number 12
- 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?
- (i) and (ii)
- (ii) and (iii)
- (iii) and (iv)
- (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?
- Atomic radius
- Metallic character
- 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.
- does not change appreciably
- 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?
- Be Mg Ca
- Na Li K
- Mg Al Si
- 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?
- Left-hand side element
Answer: (b) Metalloid