Explanation

• The First Law of Thermodynamics is also known as the Law of Conservation of Energy.
• It states that energy can neither be created nor destroyed; it can only be transferred or transformed from one form to another.
• For example, an electric heater converts electrical energy into heat energy.
• The mathematical expression is Delta U = Q - W, where Q is heat supplied and W is work done by the system.

Last verified on 09-11-2026

Explanation

• The SI unit of force is the newton (N).
• 1 N = the force needed to accelerate 1 kg of mass by 1 m/s²
• Derived unit: N = kg·m/s²
• Named after Sir Isaac Newton
• Based on F = ma (Newton's second law)

Additional information:

1. The metre, unit of length — symbol m
2. The kilogram, unit of mass — symbol kg
3. The second, unit of time — symbol s

Last verified on 09-11-2026

Explanation

• Calcium (Ca) is an alkaline earth metal belonging to Group 2 of the periodic table.
• Its atomic number is 20.
• Mercury (Hg) is a liquid metal at room temperature.
• Its atomic number is 80.
• Mercury has a boiling point of approximately 356.7°C.

Last verified on 09-11-2026

Explanation

• Isomers have the same molecular formula but different arrangements of atoms.
• They may have different structural formulas and physical properties.
• Structural isomers differ in the connectivity of their atoms.
• For example, n-butane and isobutane (C₄H₁₀) have the same molecular formula but different structures.

Last verified on 02-11-2026

Explanation

The M orbit, also known as the third electron shell.

• It can hold a maximum of 18 electrons.

Additional information:

The K orbit, also known as the first electron shell.

• It can hold a maximum of 2 electrons.

The L orbit, also known as the second electron shell.

• It can hold a maximum of 8 electrons.

Last verified on 01-11-2026