Thermal Properties of Matter in ONE SHOT for NEET 2026

Thermal Properties of Matter is an important NEET Physics chapter that covers thermometry, thermal expansion, calorimetry, and heat transfer. It includes key concepts like temperature scales, expansion formulas, and heat calculation, which are commonly asked in exams.

The chapter also explains phase change, modes of heat transfer, and radiation laws like Stefan-Boltzmann and Wien’s law. With proper formula revision and numerical practice, students can easily score 1–2 questions from this topic.

Thermal Properties of Matter in ONE SHOT for NEET 2026

Thermal Properties of Matter is an important Physics chapter for NEET that usually gives 1–2 questions every year. This ONE SHOT lecture covers the full chapter in a single session with strong conceptual clarity.

Chapter Breakdown:

• Thermometry

• Thermal Expansion

• Calorimetry

• Heat Transfer

Thermometry: Temperature Measurement & Scales

Thermometry is the measurement of temperature, which indicates how hot or cold a body is.

Temperature Scales:

• Celsius (°C): 0°C to 100°C

• Kelvin (K): 273.15 K to 373.15 K

• Fahrenheit (°F): 32°F to 212°F

Key Formulas:
TK = TC + 273.15
TF = (9/5)TC + 32

Important Points:

• Temperature difference: ΔT(K) = ΔT(°C)

• −40°C = −40°F (same value point)

• Conversion questions are common in NEET

Thermal Expansion: Length, Area & Volume

Thermal expansion is the increase in size of a material when temperature rises.

Linear Expansion:  ΔL = LαΔT

Where:
ΔL = change in length
L = original length
α = coefficient of linear expansion
ΔT = temperature change

Area Expansion: ΔA = 2αAΔT

Volume Expansion: ΔV = 3αVΔT

Key Concepts:

• Holes expand just like materials

• Percentage change = αΔT × 100

• Relation: β = 2α and γ = 3α

Special Cases in Thermal Expansion

Two Rod Condition:
If length difference remains constant: L1α1 = L2α2

Thermal Stress: Stress = YαΔT

Where: Y = Young’s modulus

Bimetallic Strip:

• Made of two metals with different expansion coefficients

• Bends on heating

• Used in thermostats

Density & Temperature Relation

ρ' ≈ ρ(1 − γΔT)

As temperature increases:

• Volume increases

• Density decreases

Effect on Pendulum

Time period formula: T = 2π√(L/g)

Key Concept:

• Temperature increase → length increases

• Time period increases

• Clock runs slow

Calorimetry: Heat & Temperature Change

Heat formula: Q = msΔT

Where:  m = mass
s = specific heat capacity

For water: s = 1 cal/g°C ≈ 4200 J/kgK

Mixing Formula: T = (m1s1T1 + m2s2T2) / (m1s1 + m2s2)

Concept: Heat lost = Heat gained

Phase Change & Latent Heat

Formula:
Q = mL

Important Values:

• Latent heat of fusion = 80 cal/g

• Latent heat of vaporization = 540 cal/g

Key Concept:
Temperature remains constant during phase change

Heat Transfer: Conduction, Convection & Radiation

Conduction Formula: ΔQ/Δt = kAΔT / L

Modes of Heat Transfer:

• Conduction: through solids

• Convection: through fluids

• Radiation: no medium required

Newton’s Law of Cooling

-dT/dt ∝ (T − T0)

Cooling rate depends on temperature difference

Stefan-Boltzmann Law

P = εσAT⁴

Power radiated depends on temperature to the fourth power

Wien’s Displacement Law

λmax T = constant

As temperature increases:

• Wavelength decreases

• Color shifts from red to white

Final Strategy for NEET 2026

Follow a smart revision and practice approach to maximize your score.

• Revise formulas daily

• Practice previous year questions

• Focus on concepts, not rote learning

• Attempt numerical problems regularly