9/14/15

Post date: Sep 11, 2015 1:47:49 PM

While we will being our week with a review of mixtures and solutions, our main focus this week will be on physical states, ( such as solids, liquids, and gases), and how heat energy can cause a change in these physical states. I have attached some reading that we will be doing throughout the week.

Here is a link to an interactive online simulation of separating mixtures and solutions:

https://www.fossweb.com/delegate/ssi-wdf-ucm-webContent/Contribution%20Folders/FOSS/multimedia/Mixtures_and_Solutions/separatingmixtures/index.html

Physical State--- This physical property is a way to describe whether a substance is a solid, a liquid, or a gas.

Solid- definite shape and volume. Molecules are tightly packed together, and can not moved very much.

Liquid- takes the shape of the container it is placed in, has a definite volume. The molecules of a liquid or slightly further apart, and have more freedom to vibrate.

Gas- neither a definite shape NOR a definite volume. This basically means that the molecules in a gas can be squished together or stretched far apart. These molecules are very far apart! They are constantly bouncing around, and have a lot of room between themselves and their neighboring molecules.

Here are some illustrations of what the inside molecules of a solid, liquid, and gas look like:

Here are some links to help you better understand each phase of matter:

NEXT we will look at how thermal energy can CHANGE these physical states!

--Thermal energy causes particles to MOVE FASTER. The FASTER THEY MOVE they more likely they are to change state. For example, in a solid, particles are not moving quickly. If you add thermal energy, they will start speeding up-- sometimes they will speed up so much, that they become a liquid! In the same way, if a liquid has enough thermal energy given to it, the particles will move fast enough to become a gas!

---On the other hand, if you have a gas ( with fast moving particles) and you take away thermal energy- the particles will slow down. As they slow down, they cool down, and become a liquid. If a liquid has thermal energy taken away, its particles might slow down enough to change it into a solid.

---These changes happen at specific points.

    • Boiling point- the temperature at which a liquid turns to a gas. For water this is at 100 degrees Celsius.

    • Melting point- the temperature at which a solid turns to a liquid. For water this is at 0 degrees Celsius.

    • Freezing point- the temperature at which a liquid turns to a solid For water this is at 0 degrees Celsius.

ALERT ALERT ALERT ALERT

THE FREEZING POINT IS THE SAME AS THE MELTING POINT! If you pass over 0 degrees, you will either MELT or FREEZE. It just depends WHICH DIRECTION you come from!!!!!

Here are some pictures and links to help you understand this subject a bit more:

On Thursday we will be taking a district test. It will measure where your students are at the beginning of fifth grade in regards to their science knowledge. I hope to review and discuss the test the next day, Friday.

Because of the test on Thursday, we will have only a vocabulary quiz on Friday instead of our usual 10 question quiz. You can find a copy of the words on this quiz in the vocabulary section of the website.

EDIT HERE IS A PRACTICE TRIPLE BEAM BALANCE TO WORK WITH:

http://www.ohaus.com/input/tutorials/tbb/TBBread.html