Heat - (1/13 - 2/17)

Summary:

States of Matter:

You may be wondering, what are the three states of matter? The three states of matter are solid, liquid and gas. An example of a solid is a pencil, and example of a liquid is apple juice or milk, and an example of a gas might be the heat coming from your soup.

Solids:

In solids, the molecules are held together by attracting and repelling like a little dance in an orderly fashion. Once the molecules start to heat up, they attract and repel faster and faster until they stop doing everything "organized" and move around freely. This causes them to melt because they cannot hold the shape anymore.

Liquids:

In liquids, the molecules are moving freely, which is why a liquid does not keep its shape except the shape of it's container. Liquids will flow due to the force of gravity. When molecules are moving slowly, they become cooler, but when they move fast they become warm. This is why, when liquids are cooled enough they turn into solids, like ice turning into water.

Gases:

In gases, the molecules are also moving freely, even more than in a liquid. Some examples of a gas would be the steam coming out of your soup, or what is inside a balloon. Gases, like liquids do not have any shape of their own, and cannot always be seen.

Evaporation:

Evaporation is the process of change from a liquid to a gas. This change in caused with more heat. In the liquid, the molecules are all moving around, but they "escape" the water and become a vapor, or a gas. Once the water becomes a vapor, you cannot see it anymore. This is why you might have to refill the water in your fish tank every so often, the water evaporates.

Condensation:

Have you ever left a glass cup on a table in cold temperatures? The water would collect on the edges of the cup. Condensation is the process of change from a gas/vapor back to a liquid. This happens when the molecules become cold enough.

Expansion and Contraction:

Have you ever left a balloon under a window on a hot day? The balloon would have gotten bigger (in other words it would expand). When the molecules heat up, they move around faster and require more space. This is what caused the balloon to get bigger. If you left a balloon under a window on a cold day, the balloon would shrink (in other words contract) because the molecules need less space on a cold day as they have less energy to move around.

Heat transfers:

There are three types of heat transfers. There is conduction, convection, and radiation. Conduction is from direct contact, radiation is transmitted through rays, and convection is a transfer of heat through a fluid.

S&EP: Developing and using models:

This week we made a foldable that talked about and gave examples of the three different types of heat transfers. This helped me understand what each heat transfer does and how it works. It also gave me an idea of what this transfer would look like and react to. We also ate three different types of popcorn. One which was made using radiation, conduction, and convection. We decided which type of popcorn was the best and why it was.