Periodic Classification of Elements Online Test 10th Science Lesson 8 Questions in English

1. The fourth group of elements consists of atomic values from 20 to 45.
2. The fourth group contains eighteen elements.
3. Ten transition elements are present in the fourth group.

• Assertion (A): The physical and chemical properties are known by the electronic configuration of the elements.
• Reasoning(R): The electronic configuration of elements occurs repeatedly.

1. Periodicity is the property of elements repeating at regular interval.
2. All the atomic properties of elements are periodic.

• Assertion (A): Metal atoms atomic radius value is known as metallic radius.
• Reasoning(R): Metallic radius is measured as half the distance between the nuclei of adjacent atoms.

1. Isolated atom radius can be easily measured.
2. Noble gas atomic radius is referred as covalent radius.

1. Ions are formed by lose or gain electrons in an atom.
2. A positively charged ion loses an electron.
3. Anion gains an electron and it is negatively charged ion.

1. Size of a cation may be smaller than the neutral atom.
2. Anion is always larger than the neutral atom.

1. The atomic size increases down the group of elements.
2. Valence electrons are tightly bound down the group.
3.  Ionization energy increases down the group in a periodic table.

1. The Electron affinity decreases from left to right in a period of the periodic table.
2. The ionization energy value decreases from top to bottom of a group in the periodic table.

• Assertion (A): The Pauling scale is used to determine the electronegativity value.
• Reasoning(R): The nature of bonding of the atoms is predicted by the Pauling scale.

• Match the electronegativity value of elements.
  1. Bromine           i) 1
  2. Sodium             ii) 2.8
  3. Chlorine            iii) 4.0
  4. Fluorine            iv) 3.0

1. The value of electronegativity along the period is increases from left to right.
2.  The electrons attracts more strongly as the nuclear charge value decreases along the period.

• Assertion (A): Ore is the mineral form of metal which can be economically extracted on a large scale.
• Reasoning(R): Minerals may be a single compound or a complex mixture of metals.

1. Oxide Ore                   i) Cuprite
2. Sulphide Ore              ii) Iron pyrite
3. Carbonate Ore            iii) Galena
4. Halide Ore                    iv) Rock salt

1. Chromite              i) Madurai
2. Lime stone          ii) Tirunelveli
3. Tungsten              iii) Cuddalore
4. Gypsum                iv) Salem
5. Titanium               v) Tiruchirappalli

• Assertion (A): Metals possess a high lustre value.
• Reasoning(R): All metals are solids at room temperature.

1. 2 Al₂O ₃ → 4 Al +3 O2↑
2. Al + H₂O → Al + H₂↑
3. Al ₂ + N ₂ → 4 Al + NO₂↑
4. Al₂O₄→ 4 Al +3 H₂O↑

1. Aluminium reacts with dry air and produces hydrogen.
2. Aluminium forms its oxide and nitride when heated at 800 °C

• Assertion (A): Aluminium reacts with steam and produces hydrogen.
• Reasoning(R): Water does not react with aluminium because of the oxide layer.

• Assertion (A): Copper dissolves in dilute HCl and H2SO4 in the presence of air.
• Reasoning(R): Without air the dilute acids does not react with copper.

1. Iron pyrite       i) Fe2O3
2. Haematite       ii) Fe3O4
3. Magnetite        iii) FeS2

• Assertion (A): The Brown hydrated ferric oxide forming on the surface of iron is called as rust.
• Reasoning(R): Exposing iron to moist air forms rust and the phenomenon is known as rusting.

• Assertion (A): Steel is used in the constructions, machineries and for transmission cables.
• Reasoning(R): Iron with 0.25%- 2.0% of carbon is used for steel.

• Assertion (A): Alloy is a heterogeneous mixture of two or more metals.
• Reasoning(R): The alkali elements of metals are used to form an alloy.

1. Iron alloys can be classified into ferrous and Non-ferrous alloys.
2. Ferrous alloys contain iron as major component.
3. Aluminum alloy is an example of Non-ferrous alloys.

• Assertion (A): Alloying is destruction of materials by electrochemical and chemical reaction with environment.
• Reasoning(R): The natural process of alloying converts metals into its oxides, hydroxide or Sulphide.

1. O₂
2. H₂O
3. H₂S
4. N₂

• Assertion (A): Wet corrosion occurs due to the presence of moisture in metals.
• Reasoning(R): The electrochemical reaction of metal with water or aqueous solution of salt, acids and bases.