Thermal Energy Transfers - Particle Nature of Matter - PDF

TOPIC: B The particulate nature of matter Chapter: Thermal energy transfers Pages: 198 Concepts/Example Activities ❖ Three states of matter are solids, liquids and gases. Each state is characterised by different properties ❖ The state of matter is determined by the separation between the mole...

TOPIC: B The particulate nature of matter Chapter: Thermal energy transfers Pages: 198 Concepts/Example Activities ❖ Three states of matter are solids, liquids and gases. Each state is characterised by different properties ❖ The state of matter is determined by the separation between the molecules, intermolecular force and the kinetic energy available to them. ❖ In solids, particles are closely packed, and the intermolecular force is the strongest. ❖ In gases the intermolecular force is the weakest. ❖ Matter can change from one state to another. During the change of state, temperature remains the same as the energy given is used up for the change of state. ❖ The sum total of all potential and kinetic energy of all the particles in a substance is called internal energy. Example Activity https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&u rl=https://phet.colorado.edu/sims/html/states-of-matter/latest/states-of -matter_all.html&ved=2ahUKEwjnrd3K9uGKAxXB_7sIHeF-LXgQFnoECA0 QAQ&usg=AOvVaw1J_ssFluxdgnBLAf788-iE  RESOURCES: Please click the link below for detailed learning https://youtu.be/L0qTSInkiHg TOPIC: B The particulate nature of matter Chapter: Thermal energy transfers (Specific heat capacity) Pages: 198 Concepts/Example Activities ❖ Two different materials have different heat capacities. ❖ To make the comparison, a physical quantity called specific heat capacity is used. ❖ The specific heat capacity of a substance is defined as the energy transfer required to raise the temperature of 1 kg of the Concepts/Example Activities c= Q m𝛥T m = mass of the substance c = specific heat capacity of the substance 𝛥T = difference in temperature ( final temperature-initial temperature) -1 -1 Unit of specific heat capacity is J kg k  RESOURCES: Please click the link below for detailed learning https://youtu.be/JTRwDcXBjnE  TOPIC: B The particulate nature of matter Chapter: Thermal energy transfers (Specific latent heat of fusion) Pages: 198 Concepts/Example Activities ❖ Specific latent heat of fusion is defined as the amount of energy transferred when 1 kg of a substance changes from one phase to another. ❖ L= Q m L is the specific latent heat of fusion. Q is the energy transferred. m is the mass of the substance. Unit of latent heat is J/kg Activities -1 0 Some crushed ice at -10 C is taken in a container and is heated. Figure below shows the variation of temperature with time. ∙ (a) What does the flat section AB of the graph represent? ∙ (b) Why does the temperature remain constant? ∙ (c)What are the two, phase changes fusion applies to?  Answer-1 (a) Flat surface indicates the change of state from ice to water. (b) Heat supplied is used to change ice from solid to liquid state. The bond between the molecules are broken during the phase change. (c) Solid to liquid and liquid to solid  RESOURCES: Please click the link below for detailed learning https://youtu.be/VG_Rc12Qg7A  TOPIC: B The particulate nature of matter Chapter: Thermal energy transfers (Specific latent heat of vaporization) Pages: 198 Concepts/Example Activities ❖ Specific latent heat of vaporisation is defined as the amount of energy transferred when 1 kg of a substance changes from one phase to another. ❖ L= Q m L is the specific latent heat of vaporisation. Q is the energy transferred. m is the mass of the substance.  RESOURCES: Please click the link below for detailed learning https://youtu.be/VG_Rc12Qg7A  TOPIC: B The particulate nature of matter Chapter: Thermal energy transfers (Thermal energy transfer) Pages: 214 Concepts/Example Activities ❖ Thermal energy transfers from hot areas to cooler areas by the process of ❖ Conduction ❖ Convection ❖ Radiation  Task-1 Provide an explanation of the information illustrated in the diagram given below. Concepts/Example Activities In conduction process, the trasfer of energy mainly takes place without the actual movement of the atoms. Conduction occurs through two mechanisms. 1. Atomic vibrations 2. Free electron collisions. Metals are good conductors due to the high number of de-localised electrons.  Task-3 Provide an explanation of the information illustrated in the diagram given below. Success Criteria ∙ Clear evidence of indicating the movement of air. ∙ Clear evidence of identifying the areas of varying densities. Concepts/Example Activities In convection process, the trasfer of energy takes place with the actual movement of the atoms due to the variation in density.  Concepts/Example Activities ❖ Convection effects explains land and sea breeze. ❖ Winds are driven by the uneven heating of the Earth’s surface. Radiation is the only method of thermal energy transfer that doesn't require matter. Radiation is the transfer of heat by means of electromagnetic radiation normally in the infra red region. Three different modes of trasfer of heat  RESOURCES: Please click the link below for detailed learning https://youtu.be/L0qTSInkiHg THANK YOU!