Variable Oxidation States

Q.

What is common feature in the electronic configuration of metal atoms

Q.

The electron which take part in order to exhibit variable Oxidation states by Transition metals are

1. (n-1)d only

2. ns only

3. ns and (n-1)d only but not np

4. (n-1)d and np only but not ns

Q. Which of the following are oxidation states that copper exhibits?

1. +1 and +3
2. +2 and +1
3. None of these
4. +1, +2 and +3

Q. Which is the most common oxidation state of lanthanides and actinide series

1. +3 only
2. +3 and +4
3. +2 and +3
4. +2 only

Q. Which of the following are true regarding oxidation states of transition elements?

1. There is a wide variability in oxidation states of transition elements
2. The variety of stable oxidation states of transition elements is made possible by the incomplete filling of d orbitals
3. neither a nor b
4. both a and b

Q. The electronic configuration $3p^6,3d^9$ represents a

1. Metal
2. Non-metal
3. Non-metallic anion
4. Metallic cation

Q. A. The elements Li, Na, and K, each having one valence electron, are in period 2, 3 and 4 respectively of modern periodic table.

(i) To which group of the modern periodic table these elements belong? [1 mark]
(ii)Which one of them is least reactive? [1 mark]
(iii) Which one of them has the largest atomic radius? [1 mark]

B. What is a chemical symbol of an element? What information does it convey? [3 marks]

C. (i) During photosynthesis, plants use light energy to prepare food. How will you classify the photosynthesis process based on the release/absorption of energy? [1 mark]

(ii) Write the chemical reaction where the following changes are observed. [3 marks]

(a) Gas is evolved

(b) Colour change is noticed

(c) Precipitate is formed

(d) Physical state is changed

Q. From +6 to +1 oxidation state is shown by element of ______ group.

1. V B
2. VI B
3. VII B
4. VIII

Q. Write the electronic configuration of K and Cl.
[TEXTBOOK QUESTION-VI(2)]

Q. Which of the following is not the correct formula?

1. $H_{2}S$
2. $NaHS{O}_4$
3. $Si{O}_2$
4. $NaSi{O}_3$

Q. The transitional metal which forms green compound in +3 oxidation state & yellow orange compound in +6 oxidation state

1. Fe
2. Ni
3. Cr
4. CO