Metals and Non-metals — Class 10 Science PYQs

The number of shells required to write the electronic configuration of Potassium (At. No. $19$)

Oxides of aluminium and zinc are :

A metal and a non-metal that exists in liquid state at the room temperature are respectively :

The oxide which can react with $\text{HCl}$ as well as $\text{KOH}$ to give corresponding salt and water is

Which of the following is an alloy of copper and tin ?

Consider the following cases :
(a) ${\text{CaSO}}_4+\text{Al}⟶$
(b) ${\text{CuSO}}_4+\text{Ca}⟶$
(c) ${\text{FeSO}}_4+\text{Cu}⟶$
(d) ${\text{ZnSO}}_4+\text{Mg}⟶$

The cases in which new products will form are -

Q. Nos. 17 to 20 are Assertion - Reason based questions :
These questions consist of two statements - Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below :
(A) Both (A) and (R) are true and (R) is the correct explanation of (A).
(B) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(C) (A) is true, but (R) is false.
(D) (A) is false, but (R) is true.

Assertion (A) : Different metals have different reactivities with water and dilute acids.

Reason (R) : Extraction of a metal from its ore depends on its position in the reactivity series.

For Q. Nos. 17 to 20, two statements are given – One labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below :
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
(b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
(c) Assertion (A) is true, but Reason (R) is false.
(d) Assertion (A) is false, but Reason (R) is true.

Assertion (A) : Hydrogen gas is not evolved when zinc reacts with nitric acid.
Reason (R) : Nitric acid oxidises the hydrogen gas produced to water and itself gets reduced.

Q. Nos. 17 to 20 are Assertion – Reason based questions :
These questions consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below :

Assertion (A) : Metals in the middle of activity series are found in nature as sulphides or carbonates.
Reason (R) : The sulphide ores are calcinated whereas carbonate ores are roasted to extract metals from them.

It is observed that Calcium on reaction with water floats on its surface. Explain why it happens. Also write a balanced chemical equation for the reaction that occurs. What happens when the aqueous solution of the product of this reaction reacts with Carbon dioxide gas ? Write a balanced chemical equation for the reaction.