Answer:
Radiation
Explanation:
There are three types of transfer of thermal energy:
- Conduction: conduction occurs when two objects/two substances are in contact with each other, and the warmer object transfers heat to the colder object through the collisions of the particles of the two objects. In this case, therefore, there is transfer of matter, so this is not the correct choice
- Convection: convection occurs in fluids. When a fluid is heated, the part of the fluid closer to the heat source gets warmer, becomes less dense and rises, replacing the colder part of fluid that sinks. Then, this part is heated, and the cycle goes on. In this type of heat transfer, there is transfer of matter, so this is not the correct choice.
- Radiation: radiation occurs when thermal energy is transferred through electromagnetic radiation. Since electromagnetic waves carry energy but not matter, in this type of heat transfer there is no overall transfer of matter. So, this is the correct answer.
Answer:
Push and pull both are forces , but the difference is in their direction at which it is applied . If the force applied in the direction of motion of the particle then we call it as push . If that force applied in the direction OPPOSITE to the motion of particle then it is termed as pull
The answer is C, because there are only so many elements therefor you can have only so many compounds.
Answer:
<em>-z axis</em>
Explanation:
According to the left hand rule for an electron in a magnetic field, hold the thumb of the left hand at a right angle to the rest of the fingers, and the rest of the fingers parallel to one another. If the thumb represents the motion of the electron, and the other fingers represent the direction of the field, then the palm will push in the direction of the force on the electron. In this case, the left hand will be held out with the thumb pointing to the right (+x axis), and the palm facing your body (-y axis). The magnetic field indicated by the other fingers will point down in the the -z axis.