Explanation

Elements or compounds that combine in a chemical reaction are called reactants.

Explanation

• Carnivores are animals that eat only meat, primarily from other animals.
• Examples of carnivores include lions, tigers, bears, wolves, and sharks.

Additional information:

• Animals that eat plants exclusively are herbivores.
• Animals that eat both plants and meat are called omnivores.

Last verified on 07-03-2026

Explanation

• Amphibians are animals that live both in water and on land.
• Most amphibians lay their eggs in water because their eggs do not have a protective shell.
• Examples of Amphibians: Frog, Toad, Salamander, Newt, Caecilian

Last verified on 07-03-2026

Explanation

• Protons and neutrons form the nucleus of an atom.
• Together, they are called nucleons because they are nuclear particles.

Additional information:

• Nucleons determine the mass of an atom.
• Isotopes are atoms of the same element with different number of neutrons.

Last verified on 07-03-2026

Explanation

• Coal is a fossil fuel because it is formed from the remains of dead plants
• It is a major source of energy.
• Used for electricity generation and industrial processes.

Explanation

Mercury is used as a thermometric fluid

Because it has several ideal properties like:

• High Boiling Point (B.P)
• Low Freezing Point (not high M.P)
• Stable and Uniform Coefficient of Expansion
• Visibility and Non-wettability

Last updated on 06-March-2026

Explanation

Force is defined by Newton’s Second Law:

***

1. Length – [L]  

2. Mass – [M]  

3. Time – [T]  

4. Speed/Velocity – [LT⁻¹]  

5. Acceleration – [LT⁻²]  

6. Force – [MLT⁻²]  

7. Work/Energy – [ML²T⁻²]  

8. Power – [ML²T⁻³]  

9. Pressure – [ML⁻¹T⁻²]  

10. Density – [ML⁻³]  

11. Momentum – [MLT⁻¹]  

12. Impulse – [MLT⁻¹]  

13. Gravitational constant (G) – [M⁻¹L³T⁻²]  

14. Planck’s constant (h) – [ML²T⁻¹]  

15. Charge – [TI] (T = time, I = current)  

16. Potential difference (Voltage) – [ML²T⁻³A⁻¹]  

17. Electric current – [I]  

18. Electric resistance – [ML²T⁻³A⁻²]  

19. Capacitance – [M⁻¹L⁻²T⁴A²]  

20. Magnetic field (B) – [MT⁻²A⁻¹]

Explanation

• The atomic number of oxygen is 8.
• This indicates that an oxygen atom contains 8 protons in its nucleus. 
• Atomic Symbol: O
• Position: Located in Group 16 of the periodic table.
• Oxygen is a chemical element.
• Discoverers: Joseph Priestley, Antoine Lavoisier, Carl Wilhelm Scheele

Oxygen Electrons per shell: 2, 6

Last updated on 06-March-2026

Explanation

• Non-luminous objects do not produce their own light; they are visible because they reflect light from other sources.
• The Moon is non-luminous; it reflects sunlight.
• Luminous objects like the Sun, stars, and fireflies produce their own light.

Last verified on 06-03-2026

Explanation