1. What is the lightest element in the periodic table?
- Helium
- Hydrogen
- Lithium
- Boron
Explanation:
- Hydrogen is the lightest element (Atomic number 1).
- Helium is the second lightest (Atomic number 2).
- Lithium is heavier with Atomic number 3.
- Boron has Atomic number 5.
2. Which element has the highest atomic number currently known?
- Uranium
- Oganesson
- Copernicium
- Oganesson
Explanation:
- Oganesson (Og) has the highest atomic number: 118.
- Uranium is 92.
- Copernicium is 112.
- All are heavy elements, but Oganesson is the heaviest.
3. Which element is known as the ‘king of chemicals’?
- Oxygen
- Sulphuric acid (H2SO4)
- Nitrogen
- Chlorine
Explanation:
- Sulphuric acid is called the king of chemicals as it is widely used in industry.
- Oxygen and Nitrogen are abundant gases.
- Chlorine is used for water purification.
4. Which is the most abundant element in the Earth’s crust?
- Silicon
- Aluminium
- Oxygen
- Iron
Explanation:
- Oxygen (about 46%) is the most abundant element in Earth’s crust.
- Silicon comes second (about 27%).
- Aluminium and Iron are less abundant.
5. What is the symbol of Potassium?
- Po
- K
- P
- Pt
Explanation:
- K is derived from Latin name Kalium.
- Po is Polonium.
- P is Phosphorus.
- Pt is Platinum.
6. Which element is liquid at room temperature?
- Cesium
- Bromine
- Iodine
- Gallium
Explanation:
- Bromine is a liquid halogen at room temperature.
- Cesium and Gallium melt just above room temperature.
- Iodine is solid at room temperature.
7. Which noble gas has the lowest atomic number?
- Neon
- Argon
- Helium
- Krypton
Explanation:
- Helium has atomic number 2, lowest among noble gases.
- Neon (10), Argon (18), Krypton (36) are heavier.
8. What is the atomic number of Carbon?
- 5
- 6
- 7
- 8
Explanation:
- Carbon has atomic number 6.
- Boron = 5, Nitrogen = 7, Oxygen = 8.
9. Which element has the chemical symbol ‘Fe’?
- Fluorine
- Iron
- Francium
- Fermium
Explanation:
- Fe = Iron from Latin ‘Ferrum’.
- Fluorine = F.
- Francium = Fr.
- Fermium = Fm.
10. Which alkali metal is the lightest?
- Sodium
- Lithium
- Potassium
- Rubidium
Explanation:
- Lithium is the lightest alkali metal (Atomic number 3).
- Sodium (11), Potassium (19), Rubidium (37) are heavier.
11. Which element is used in making semiconductors?
- Carbon
- Silicon
- Aluminium
- Magnesium
Explanation:
- Silicon is the most widely used semiconductor material.
- Carbon is used in graphite/electrodes, not semiconductors.
12. Which gas is known as ‘laughing gas’?
- Carbon dioxide
- Nitrous oxide
- Ozone
- Helium
Explanation:
- Nitrous oxide (N2O) is laughing gas.
- Carbon dioxide is used in fire extinguishers.
- Ozone protects from UV radiation.
13. Which is the hardest natural element?
- Quartz
- Diamond
- Corundum
- Silicon carbide
Explanation:
- Diamond, an allotrope of carbon, is the hardest naturally occurring material.
14. Which element is essential for hemoglobin?
- Calcium
- Magnesium
- Iron
- Zinc
Explanation:
- Iron is essential for hemoglobin in blood.
- Calcium = bones, Magnesium = chlorophyll, Zinc = enzymes.
15. Which element is known as quicksilver?
- Silver
- Mercury
- Platinum
- Lead
Explanation:
- Mercury is also called quicksilver.
16. Which element is the best conductor of electricity?
- Gold
- Silver
- Copper
- Aluminium
Explanation:
- Silver is the best conductor of electricity.
- Copper and Aluminium are widely used due to cost-effectiveness.
17. Which element is known as the ‘building block of life’?
- Oxygen
- Carbon
- Hydrogen
- Nitrogen
Explanation:
- Carbon forms the basis of organic life compounds.
18. Which element is used in nuclear reactors as fuel?
- Thorium
- Plutonium
- Uranium
- Radium
Explanation:
- Uranium-235 is commonly used in nuclear reactors.
19. Which element is stored in kerosene?
- Sodium
- Sodium and Potassium
- Lithium
- Calcium
Explanation:
- Sodium and Potassium are stored in kerosene to prevent reaction with air/moisture.
20. Which element has the highest melting point?
- Osmium
- Tungsten
- Iron
- Carbon
Explanation:
- Tungsten has the highest melting point (3422 °C).
21. Which gas is used in balloons?
- Hydrogen
- Helium
- Oxygen
- Nitrogen
Explanation:
- Helium is used as it is lighter than air and non-flammable.
- Hydrogen is lighter but flammable, so unsafe.
22. Which element was discovered by Marie Curie?
- Radium
- Uranium
- Polonium
- Thorium
Explanation:
- Radium and Polonium were discovered by Marie Curie, but Radium is most famous.
23. Which is the most reactive metal?
- Sodium
- Calcium
- Francium
- Potassium
Explanation:
- Francium is the most reactive alkali metal (though rare).
24. Which element has the symbol ‘Na’?
- Nitrogen
- Sodium
- Neon
- Nickel
Explanation:
- Na comes from Latin word Natrium (Sodium).
25. Which is the lightest noble gas?
- Neon
- Helium
- Argon
- Krypton
Explanation:
- Helium is the lightest noble gas.
1. What is the lightest element in the periodic table?
- Helium
- Hydrogen
- Lithium
- Boron
Explanation:
- Hydrogen (atomic number 1) is the lightest element.
- Helium is the second lightest.
- Lithium and Boron are much heavier in comparison.
2. Which element has the highest atomic number naturally found on Earth?
- Uranium
- Thorium
- Uranium
- Plutonium
Explanation:
- Uranium (92) is the heaviest naturally occurring element.
- Plutonium and others are synthetic.
3. Which group in the periodic table is known as Noble Gases?
- Group 1
- Group 2
- Group 17
- Group 18
Explanation:
- Group 18 elements (He, Ne, Ar, Kr, Xe, Rn) are noble gases.
- Group 1 are Alkali metals.
- Group 17 are Halogens.
4. Which element has the highest electronegativity?
- Oxygen
- Nitrogen
- Fluorine
- Chlorine
Explanation:
- Fluorine (3.98) has the highest electronegativity.
- Oxygen and Nitrogen are lower.
5. What is the atomic number of Carbon?
- 8
- 10
- 6
- 7
Explanation:
- Carbon has atomic number 6.
- Oxygen = 8, Nitrogen = 7.
6. Which period contains the maximum number of elements?
- Period 1
- Period 2
- Period 6
- Period 4
Explanation:
- Period 6 has 32 elements (includes Lanthanides).
- Period 1 has only 2 elements.
7. What is the symbol of Potassium?
- Pt
- K
- P
- Po
Explanation:
- K is Potassium (from Latin “Kalium”).
- Pt is Platinum, Po is Polonium.
8. Which is the most abundant metal in Earth’s crust?
- Iron
- Aluminium
- Copper
- Sodium
Explanation:
- Aluminium is the most abundant metal.
- Iron is second most abundant metal.
9. Which element is liquid at room temperature?
- Bromine
- Chlorine
- Bromine
- Iodine
Explanation:
- Bromine is a liquid non-metal.
- Mercury is the liquid metal.
10. Which block contains transition metals?
- s-block
- d-block
- p-block
- f-block
Explanation:
- d-block elements are transition metals.
11. What is the symbol of Gold?
- Ag
- Au
- G
- Go
Explanation:
- Au (from Latin “Aurum”) is Gold.
- Ag is Silver.
12. What is the atomic number of Oxygen?
- 7
- 9
- 8
- 10
Explanation:
- Oxygen = 8.
13. What is the lightest noble gas?
- Neon
- Helium
- Argon
- Krypton
Explanation:
- Helium is the lightest noble gas (atomic number 2).
14. Which halogen is solid at room temperature?
- Chlorine
- Bromine
- Iodine
- Fluorine
Explanation:
- Iodine is a violet-black solid.
15. Which element is called ‘King of Chemicals’?
- Sodium
- Sulphuric Acid (H₂SO₄)
- Chlorine
- Carbon
Explanation:
- Sulphuric acid is widely used, hence called King of Chemicals.
16. What is the atomic number of Sodium?
- 10
- 12
- 11
- 9
Explanation:
- Sodium = 11.
17. Which element is known as the “Greenhouse gas element” in CO₂?
- Hydrogen
- Oxygen
- Carbon
- Nitrogen
Explanation:
- Carbon is key in CO₂ greenhouse gas.
18. Which metal is liquid at room temperature?
- Gallium
- Mercury
- Cesium
- Sodium
Explanation:
- Mercury is liquid at room temperature.
19. Which element is most abundant in the Earth’s crust?
- Iron
- Calcium
- Oxygen
- Silicon
Explanation:
- Oxygen (46.6%) is most abundant in Earth’s crust.
20. Which is the first element of the p-block?
- Boron
- Carbon
- Aluminium
- Nitrogen
Explanation:
- Boron is the first element of the p-block.
21. Which group is called Alkali metals?
- Group 17
- Group 1
- Group 18
- Group 2
Explanation:
- Group 1 elements are Alkali metals.
22. What is the heaviest halogen?
- Iodine
- Astatine
- Bromine
- Fluorine
Explanation:
- Astatine is the heaviest halogen (rare, radioactive).
23. What is the atomic number of Iron?
- 25
- 27
- 26
- 28
Explanation:
- Iron = 26.
24. Which element has the chemical symbol ‘Ag’?
- Gold
- Silver
- Argon
- Aluminium
Explanation:
- Ag = Silver (from Latin “Argentum”).
25. What is the atomic number of Helium?
- 1
- 3
- 2
- 4
Explanation:
- Helium = 2.