Grade 10 : Science - 3. Metals/Non-Metals (Set 2) | Concept of Maths

Question 1

Rohan wants to protect his outdoor iron gates from rusting due to seasonal rain. He decides to coat the iron with a protective layer of Zinc (Zn). What is this practical chemical process called?

Accepted Answer

B) Galvanization

Answer

A) Anodizing

Answer

C) Alloying

Answer

D) Electroplating with Copper

Question 2

During a home renovation, Priya notices that electrical wires are made of Copper (Cu) but are covered with a colorful outer layer of Polyvinyl Chloride (PVC). What is the primary safety reason for this PVC layer?

Accepted Answer

B) PVC is an insulator (poor conductor of electricity) that prevents electric shocks.

Answer

A) It makes the copper wire more flexible and easier to pull through walls.

Answer

C) It increases the overall electrical conductivity of the copper wire.

Answer

D) It prevents the copper from reacting with noble gases in the surrounding air.

Question 3

Ananya is buying a gold necklace. The jeweler explains that pure gold (24-carat) is too soft and bends out of shape easily, so they alloy it with other metals to make 22-carat gold. Which metals are commonly mixed with gold for this purpose?

Accepted Answer

B) Copper or Silver

Answer

A) Sodium or Potassium

Answer

C) Lead or Tin

Answer

D) Mercury or Zinc

Question 4

Amit is watching a railway maintenance crew repair a cracked steel track. They mix Iron(III) oxide ($Fe_2O_3$) with a highly reactive metal powder and ignite it. The intense heat melts the iron, which flows into and seals the crack. Which metal powder is used in this Thermite process?

Accepted Answer

B) Aluminium (Al)

Answer

A) Copper (Cu)

Answer

C) Platinum (Pt)

Answer

D) Lead (Pb)

Question 5

Sneha wraps her school lunch in a very thin sheet of Aluminium foil to keep it warm and fresh. Which physical property of Aluminium allows it to be beaten into such extremely thin foils?

Accepted Answer

C) Malleability

Answer

A) Ductility

Answer

B) Sonority

Answer

D) High melting point

Question 6

A professional chef prefers using stainless steel cooking pans that have a thick copper bottom plate. What is the main scientific advantage of having a copper base?

Accepted Answer

A) Copper is a much better conductor of heat than stainless steel, ensuring rapid and even cooking.

Answer

B) Copper reacts chemically with food to make it cook faster.

Answer

C) Copper prevents the outer surface from getting scratched.

Answer

D) Copper decreases the overall weight of the pan.

Question 7

While visiting a school clinic, Kabir observes a thermometer containing a silver-colored liquid metal. Which metal remains liquid at room temperature ($25^\circ\C$) and is used in thermometers?

Accepted Answer

B) Mercury (Hg)

Answer

A) Sodium (Na)

Answer

C) Gallium (Ga)

Answer

D) Bromine (Br)

Question 8

To light a candle, Rohit strikes a safety match against the rough red-brown chemical strip on the side of the matchbox. Which non-metal allotrope is primarily responsible for initiating this ignition on the striking surface?

Accepted Answer

B) Red Phosphorus

Answer

A) Sulfur

Answer

C) Graphite

Answer

D) Silicon

Question 9

In a chemistry laboratory, the teacher shows the students a jar containing soft silver-grey Sodium (Na) metal stored completely immersed in kerosene oil. Why is Sodium kept in kerosene?

Accepted Answer

A) To prevent it from reacting violently with atmospheric moisture and oxygen.

Answer

B) To keep it soft so it can be easily cut with a knife.

Answer

C) To increase its melting and boiling points.

Answer

D) To help it conduct electricity better.

Question 10

For an elementary physics project, Lisa connects a 9\V battery and a small light bulb using the graphite core (pencil lead) of a wooden pencil. The bulb glows! Which characteristic of the non-metal Carbon in the form of Graphite explains this behavior?

Accepted Answer

C) It has free, delocalized electrons that allow it to conduct electricity.

Answer

A) It has a high density.

Answer

B) It has giant covalent bonds making it transparent.

Answer

D) It is highly malleable and ductile.