Metals And Non-Metals Study Question Class-7th Goyal Brothers ICSE Chemistry Solutions Chapter-6 Unit-1

Metals And Non-Metals Study Question Class-7th Goyal Brothers ICSE Chemistry Solutions Chapter-6 Unit-1 We Provide Step by Step Answers of Study Question of Chapter-6 (Metals And Non-Metals ) Unit-1. Visit official Website  CISCE  for detail information about ICSE Board Class-7.

Metals And Non-Metals ICSE Class-7th Goyal Brothers Chemistry Study Question Solutions Chapter-6 Unit-1

Board ICSE
Class 7th
Subject

Chemistry

Book Name Goyal Brothers
Chapter-6 Metals And Non-metals
Unit-1

Metals And Non-metals

Topic Solution of exercise questions
Session 2023-24

STUDY QUESTIONS

Metals And Non-Metals ICSE Class-7th Goyal Brothers Chemistry Solutions Chapter-6 Unit-1

Question: 1. (a) What do you understand by the term metal?

Answer: Metals:- The substances which are typically solid, hard, ductile (can be drawn into wires), and malleable (can be drawn into sheets) and have high thermal conductivity and electricity are known as metals. Metals generally form cations by donating electrons to electron acceptors (non-metals) Example – Gold(Au), and Copper(Cu).

(b) State any five physical properties of a metal.

Answer: Five physical properties of metals are:

  • Metals are malleable and ductile.
  • Metals are good conductors of heat and electricity.
  • Metals are lustrous (shiny) and can be polished.
  • Metals are solids at room temperature (except mercury, which is liquid).
  • Metals are tough and strong.

Question: 2. (a) Name one metal which is a liquid at room temperature.

Answer: Mercury a metal which is a liquid at room temperature.

(b) Name a metal which can be cut with a knife.

Answer: Sodium and Potassium metals a metal which can be cut with a knife.

(c) Name a metal which is lighter than water.

Answer: Lithium a metal which is lighter than water.

(d) Name a metal which in not malleable.

Answer: zinc, arsenic, mercury, antimony a metal which in not malleable.

(e) Name a metal which is the best conductor of electricity.

Answer: Silver a metal which is the best conductor of electricity.

(f) Name a metal which is poor conductor of electricity.

Answer: Iron (Fe),  Mercury (Hg), Tungsten (W) a metal which is poor conductor of electricity.

Question: 3. State two important uses of following metals :

(a) Gold

Answer: (i) Gold is used in making jewelry and ornaments.

(ii) It is employed in filling tooth cavities (dentistry).

(b) Silver

Answer: (i) Silver is used in the manufacturing of coins and ornaments.

(ii) Salts of silver like silver bromide are used in making photographic plates because silver halides are light-sensitive.

(c) Copper

Answer: (i) It is used for making electric transmission wires.

(ii) It is used for making utensils.
(d) Iron

Answer: (i) Plumbing pipes used in our houses are generally made of iron.

(ii) Being a very strong material, iron is often used to make parts of automobiles.

(e) Tin

Answer: (i) It is used for tinning food cans and the cooking vessels made from copper or iron.

(ii) It is used for making alloys, such as bronze.
(f) Zinc

Answer: (i) Zinc is used in prevention of rusting of iron sheets. The process of coating iron sheets with molten zinc is known as galvanization.

(ii) Zinc is used in making alloys such as brass.

(g) Aluminum 

Answer: (i) Aluminum is light weight , hence it is used in making of alloys like magnalium.

(ii) Aluminum is used in making of aluminum foil for packaging food as it is heat resistant.

(h) Lead

Answer: (i) It is employed in making sanitary pipes.

(ii) It is employed in preparation of lead acid batteries used in automobiles.

(i) Magnesium

Answer: (i) Magnesium is used in fireworks as it burns with a brilliant luminescence and dazzling white flame.

(ii) It is used in the making of alloys such as magnalium which is used as a frame of airplanes.

(j) Mercury 

Answer: (i) It is used for filling tooth cavities (dentistry).

(ii) It is employed in the use of thermometric liquids.

Question: 4. (a) What do you understand by the term non-metal?

Answer: Non-metals are those which lack all the metallic attributes. They are good insulators of heat and electricity. They are mostly gases and sometimes liquid. Some of then are even solid at room temperature like Carbon, sulphur and phosphorus.

(b) State any five physical properties of a non-metal.

Answer: Five physical properties of non-metals are:

  • Non-metals are brittle.
  • Non-metals are bad conductors of heat and electricity (except graphite).
  • Non-metals are non-lustrous (dull) and cannot be polished (except iodine).
  • Non-metals may be solids, liquids or gases at room temperature.
  • Non-metals are neither tough nor strong.

Question: 5. (a) Name the non-metal and its natural form, which is the hardest substance.

Answer: Diamond is the hardest non-metal. Diamond is an allotrope of carbon (C) and its atoms are arranged in a crystal. It is a naturally occurring substance and the hardest non-metal.

(b) Name a non-metal which is liquid form at room temperature.

Answer: Bromine a non-metal which is liquid form at room temperature.

(c) Name a non-metal which is good conductor of electricity.

Answer: Graphite a non-metal which is good conductor of electricity.

(e) Name a non-metal whose compounds help in the growth of plants.

Answer: Nitrogen a non-metal whose compounds help in the growth of plants.

Question: 6. State two important uses of following non-metals :

(a) Nitrogen

Answer: (i) Nitrogen is used for making plant fertilizers as it helps in the growth and development of plants.

(ii) Nitrogen is use in making of nitric acid in laboratory.

(b) Oxygen

Answer: (i) Oxygen is the most important gas and supports the survival of living beings by aiding in the respiration process.

(ii) Oxygen is necessary for the combustion of fuels. The combustion of fuel provides carbon dioxide and water vapor as products.

(c) Chlorine

Answer: (i) Chlorine is used as a sterilizing agent for drinking water as it kills certain bacteria and other harmful microorganisms making water potable for drinking purposes.

(ii) Chlorine is employed as a bleaching agent (removing of natural colours) from cotton and jute fabrics.

(d) Iodine

Answer: (i) Sodium iodide in salt extract is used in manufacture of common salt. It is used so that the normal functioning of body is maintained and iodine deficiency is recovered.

(ii) Iodine is used in preparation of iodoform which is used in medicine.

(e) Graphite

Answer: (i) Graphite is used as a pencil lead because it is soft and imparts an impression on paper.

(ii) Graphite is used as a lubricant (grease) because it is slippery in nature and the slippery property is attributed to the presence of layered structured and the layers has weak intermolecular force present between them , hence layers can rapidly slip past over each other.

Question: 7. (a) What are noble gases? Name all in the order of their increasing density.

Answer: Noble gases are the gases which belong to group 18 of the periodic table and are highly non -reactive species as they have their valence shell completely filled , hence they do not tend to react and do not form any bond with out elements. Density Order of Noble gases :The name of all the noble gases according to their increasing order of their densities are given as Helium <Neon < Argon < Krypton < Xenon < Radon.

(b) State one use each of  (i) Helium (ii) Argon.

Answer: (i) Helium: Helium is used to provide an inert protective atmosphere for making fiber optics and semiconductors, and for arc welding.

(ii) Argon: Argon can be used as a carrier gas in cinematography.

Question: 8. (a) What is an alloy?

Answer: The meaning of the term ‘alloy’ is a substance formed from the combination of two or more metals. Alloys can also be formed from combinations of metals and other elements.

(b) Why are alloys made?

Answer: Pure metals generally do not have all the properties of good metal, such as malleability, ductility, tensile strength, hardness, resistance to corrosion, etc. Hence, alloys are made to enhance these properties. An alloy will have a better quality than the individual metals (or a non-metal) that form it.

Question: 9. State the composition and two uses of following alloys :

(a) Stainless steel

Answer: Stainless steel: It is an alloy of  % iron,  % carbon,  % chromium and  % nickel.

Two uses of stainless steel:

(i) It is used for making household utensils.
(ii) It is used for making surgical instruments.
(b) Duralumin

Answer: Duralumin : It is an alloy of  % aluminum,  % copper,  % manganese and  % magnesium.

Two uses of Duralumin :
(i) It is used for making aircraft frames.
(ii) It is sued for making household articles.
(c) Brass

Answer: Brass: It is an alloy of  % to  % zinc and  % to  % copper.

Two uses of brass:

(i) It is used for making tap and electric switches.
(ii) It is used for making household utensils.
(d) Bronze

Answer: Bronze: It is an alloy of  % copper,  % zinc and  % tin.

Two uses of Bronze:
(i) It is used for making statues.
(ii) It is used for making household utensils.

Question: 10. What is an amalgam? How does an amalgam deferrer from an alloy?

Answer: Amalgam is an alloy of mercury with one or more metals. Sodium along with liquid mercury is known as sodium amalgam. Amalgam of mercury with tin, silver and zinc is widely used in dental filling. Amalgam is an alloy of a metal with mercury.

Question: 11. (a) Define rusting of iron.

Answer: When iron is left exposed to moist air, it undergoes a chemical change leading to the formation of a brown powdered mass on the iron, leading to the occurrence of a phenomenon known as rusting. Rusting Takes place only in moist air when there is intimate contact between water, oxygen, and iron. The process of rusting can be represented by the following equation

Fe(s)      +       O2(g)      +      H2O(l)      →       Fe2O3.xH2O(s)

Iron              Oxygen               Water                       Rust

(b) State at least three methods of preventing rusting.

Answer: The rusting of iron can be prevented by the following methods:

(1) Iron surface is coated with paint. It is a temporary solution. The iron surface is shielded from oxygen and moisture.
(2) Iron is coated with another metal such as zinc. The process is called galvanizing. Zinc is stronger reducing agent than iron and hence preferentially oxidized.
(3) An alloy of  with  is formed. This alloy is stainless steel. It reduces the tendency of iron to oxidized.

Question: 12. (a) What are metalloids? Name at least three metalloids.

Answer: Elements can be classified as metals, metalloids, or non-metals. Metalloids are the elements that show the properties of both metals and non-metals.

Name of three metalloids:-

  • Silicon – It is a hard crystalline solid with blue grey metallic luster and is brittle like non -metal
  • Antimony – It is silvery white metal shiny like metal but brittle like non -metal
  • Germanium – It is lustrous and hard white element like metal but is brittle like non -metals.

(b) State uses of two common metalloids.

Answer: Two common metalloids:

1) Silicon – It is a bluish -grey crystalline solid with a metallic luster similar to metals , but is brittle like non metals.

  • It is used in making of microprocessor chips
  • It is used in making a waterproof polymer silicone
  • Silicon carbide , the hardest substance is used in abrasives.

2) Antimony – It is silvery white lustrous element which makes it similar to metals and is brittle which gives its resemblance to non -metals

  • It is used in electronic industry as semiconductor device
  • It is used as a typing metal in printing press.

— : end of Metals And Non-Metals ICSE Class-7th Goyal Brothers Chemistry Study Question Solutions Chapter-6 Unit-1:–-

Return to –  ICSE Class -7 Goyal Brothers Chemistry Solutions

Thanks

Please share with your friends if you find it useful

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.