here are some science questions I've been trying to do for over an hour and i just cant figure them out!

1.how does a fan convert energy?
2.what happens to matter during both a physical and chemical change?
3.give an example of a simple closed system
4. in a fire, why does the wood have less mass after the fire is done?

thanks! :)

1.fan converts the electrical energy into kinetic energy. this kinetic energy causes the wind to blow..

2.physical change-no change in composition. Ice melts, water boils, water condenses to liquid, liquid freezes.

chemical change- chemical composition changes.

Wood burns to give carbon dioxide, carbon dioxide, smoke, wood ash. No reverse reactions possible.
3. ?
4.The mass loss is due to the burning, which both drives out water and other fluids by converting them to vapor, and gasses like carbon dioxide when oxygen in the air combines with carbon in the log. A very small amount of mass is also converted into energy, and radiated from the log.

I am not a tutor and I googled the answers

i don't understand how you got the answer to number 2. is matter the composition?

1. How does a fan convert energy?

To understand how a fan converts energy, we need to know that fans are powered by electricity. When you plug in a fan and switch it on, the electricity flows through the wires to the motor of the fan. The motor converts electrical energy into mechanical energy. This mechanical energy is then used to rotate the fan blades, creating airflow and cooling effect. So, the fan converts electrical energy into kinetic energy, which is the energy of motion.

2. What happens to matter during both a physical and chemical change?
During a physical change, the arrangement or state of matter may change, but the fundamental chemical composition remains the same. For example, when water freezes, its state changes from liquid to solid, but the chemical composition remains H2O.

On the other hand, during a chemical change, there is a rearrangement of atoms and molecules, resulting in the formation of new substances with different chemical compositions. For instance, when wood burns, it undergoes a chemical change called combustion, and the wood is transformed into carbon dioxide, water vapor, and other byproducts.

3. Give an example of a simple closed system.
A simple closed system can be a sealed container with fixed boundaries that does not allow the exchange of matter with its surroundings, although energy can still flow in or out. One example of a simple closed system could be a sealed glass jar filled with air. The air molecules inside the jar can move and interact with one another, but no air enters or leaves the container.

4. In a fire, why does the wood have less mass after the fire is done?
When wood burns, it undergoes a chemical reaction known as combustion. During combustion, the wood reacts with oxygen in the air, producing heat, light, carbon dioxide, water vapor, and other substances as byproducts. Some of the carbon in the wood combines with oxygen from the air to form carbon dioxide, which is a gas that escapes into the surrounding atmosphere. Additionally, the water content in the wood also evaporates due to the heat of the fire, further reducing the mass of the wood. As a result, the wood loses mass after the fire is done due to the release of gases and the evaporation of water.