Maharashtra Board Class 10 Science and Technology Part-1 Question Paper 2025 (Code N 840) Available- Download Here with Solution PDF

(A) Choose the correct alternative:
(i) Alkaline earth metals have valency 2. This means that their position in the modern periodic table is in ________ .

• (A) Group 2
• (B) Group 16
• (C) Period 2
• (D) d-block

(ii) The reaction in which ions in the reactants are exchanged to form a precipitate is called as ______ reaction.

• (A) Combination
• (B) Decomposition
• (C) Displacement
• (D) Double Displacement

(iii) _______ is used to make a solenoid type coil in an electric bulb.

• (A) Nichrome
• (B) Copper
• (C) Tungsten
• (D) Aluminium

(iv) Light changes its direction when going from one transparent medium to another transparent medium. This process is called _______ .

• (A) Reflection
• (B) Dispersion
• (C) Scattering
• (D) Refraction

(v) CaO + H\(_2\)O \(\rightarrow\) Ca(OH)\(_2\) + Heat is an example of ................. reaction.

• (A) Exothermic
• (B) Electrolysis
• (C) Decomposition
• (D) Endothermic

(i) State whether true or false:
A redox reaction takes place during cellular respiration.

(v) Name the behaviour of water between its temperature from 0°C to 4°C.

(i) While going from left to right within a period, the size of the atom decreases.

(ii) For electric power transmission, copper or aluminium wire is used.

(i) Name and state the principle used to measure the specific heat capacity of a substance.

(ii) What is done to prevent rusting of iron door of your house?

• (A) Applying Paint, Oil, or Grease Coating: One of the most common methods to prevent rusting is by applying a protective layer of paint, oil, or grease. This coating prevents the direct contact of iron with moisture and oxygen in the environment, thus stopping the rusting process.
• (B) Galvanization (Coating with Zinc): Galvanization involves coating the iron or steel with a thin layer of zinc. The zinc acts as a sacrificial anode, corroding instead of the iron. Even if the coating is scratched, the zinc will continue to protect the exposed iron.
• (C) Electroplating with Another Metal: Another method is electroplating the iron surface with a corrosion-resistant metal such as chromium or nickel. This adds a protective metallic layer that prevents the iron from coming into contact with corrosive agents.

(iv) The ‘rocket’ is a type of fire cracker used in Diwali.

• (a) Name the launcher.

(v) What is meant by decomposition reaction? Write the chemical reaction of decomposition of sugar on heating.

(i) An iron ball of mass 3 kg is released from a height of 125 m and falls freely to the ground. Assuming that the value of \(g\) is 10 m/s\(^2\), calculate:

• (a) Time taken by the ball to reach the ground.

(ii) Write the name and symbol of the element from the description:

(vi) Name the following:

• (a) The two metals which can be cut with knife.
  Answer: Sodium (Na) and Potassium (K). Sodium and potassium are both alkali metals that are soft enough to be cut with a knife. These metals have a low melting point and low density, which makes them soft and easy to cut. They are highly reactive, especially with water, which is why they are stored under oil to prevent contact with moisture in the air.
• (b) A sound is produced when certain metals are struck. Name this property of metals.
  Answer: Sonorous. The property of metals that allows them to produce sound when struck is called sonority}. Metals like iron, copper, and steel are sonorous, meaning they produce a ringing sound when struck. This property is due to their ability to vibrate freely, producing sound waves.