In the first situation: the mechanism of covection is the main form of heat transfer when warm air from a heater moves around and upward.
In the case of the metal pan the mechanism of heat transfer is conduction.
In the case of sunburn the mechanism is radiation.
In the case of an ice cube melting in a hand, conduction is the most important mechanism.
The answer is AIM NOT POSTIVE
Answer:
Valence Electrons are transferred/exchanged
Explanation:
A substance burning in the presence of oxygen and leads to the formation of heat and light is called combustion.
Some important points about combustion are as follows:
- Fuel should be present for burning.
- Air should be present for the supply of oxygen.
- There should be heat (or ignition temperature) to initiate the chemical reaction.
Answer:
a chemical reaction or other process in which the products themselves promote or spread the reaction, which under certain conditions may accelerate dramatically.
Explanation:
the self-sustaining fission reaction spread by neutrons which occurs in nuclear reactors and bombs.
a series of events, each caused by the previous one.
