Answer:
1. The Sun, reflected sunlight from planets and moons, heating by friction when traveling through an atmosphere or gas clouds, and released heat from planets.
2. The gas is heated and allowed to expand at such a rate that the fall in temperature due to expansion is less than the rise in temperature due to the heat supplied.
3. Prolonged exposure to extreme heat can cause heat exhaustion, heat cramps, heat stroke, and death, as well as exacerbate preexisting chronic conditions, such as various respiratory, cerebral, and cardiovascular diseases.
4. The thermal resistance is defined as the ratio of the temperature difference, dT, to the heat transfer Q. This is analogous to Ohm's law, in which the electrical resistance is defined as the ratio of the voltage drop across a resistor to the current flow across the resistor.
5. Heat energy is the result of the movement of tiny particles called atoms, molecules or ions in solids, liquids and gases. Heat energy can be transferred from one object to another. The transfer or flow due to the difference in temperature between the two objects is called heat.
There you go :D.