Elements, Mixtures & Compounds!

Today in class we had Mr. Tim as our teacher because Ms. D went on a field trip with the 7th graders.Mr. Tim discussed elements, compounds, and mixtures to us.

An element: a substance which cannot be broken down into other substances by ordinary chemicals. Each element is represent by a symbol. Example: oxygen = O , gold = Au, helium= He

Here is a link to "The Element Song" http://www.youtube.com/watch?v=GFIvXVMbII0

A compound: two or more elements can be combined to form compounds. Compounds are very different from the elements from which they are formed. Example:NaCl, made from sodium, a dangerous and explosive element, and chlorine, a poisonous gas.

A mixture: made from two or more substances, elements, compounds, or both in definite proportions, and these proportions are not always the same. Example: soil, cake, milk

Homogeneous mixture: the substances in a homogeneous mixture are so evenly mixed that you can't see the different parts. Example: cake batter, petrol, plastic spoon

Heterogeneous mixture: in a heterogeneous mixture you can see the different parts. Example: salad, gravel, car

After discussing those topics, we reviewed temperature, weight, mass, volume, and density. We gave a definition, units, and the equipment used for each property.

Temperature: - a measure of the average NRG of motion of the particles of a substance

- Celsius and Kelvin

- thermometer

Weight: - a measure of the force of gravity on an object.

- Newtons, kilograms

- force scale, spring scale

Mass: - a measure of how much matter is in an object.

- kilograms

- TBB

Volume: - the amount of space that matter occupies.
-centimeters cubed
-ruler, graduated cylinder
Density: - the measurement of how much mass of a substance is contained in a given volume
-TBB, ruler

Finally we got to our rotation lab on matter. In this lab we had to smell and examine 12 different substances and write down their symbol/formula, their physical properties, decide if the substance was a solid, liquid or gas and decide if it was an element, compound or mixture.

Here are some substances that were examined: ^.

• Copper- Cu, solid, element

• Hydrogen peroxide- H₂O₂ , liquid, compound 
• Rubbing Alcohol-C₃H₈O, Liquid, compound

The homework from today is to complete "States of Matter-pg 42-47" and by reading those pages fill out States of Matter Note Taking Section in our Chemistry Packet.

Also don't forget another blog comment is due tomorrow (Friday).

The next scriber is Alex.

Reflection Post

Well this was my first blogging experience. It is definitely a good way to share things to others around the world. It’s pretty simple to use and understand. I will admit, in the beginning it was a bit hard because Blogger was set to the Croatian language, so it was hard for me to understand it. Thankfully I found out how to change the language, so that made it easier. Another challenge was getting the pictures into a blog post. For some people it worked fine, for others it did not. But even though the pictures did not cooperate so well for me, writing the actual post and making comments was easy and worked fine. This blog is something that will be helpful when a class mate is sick and missed work. Blogger also allows us to see what the other Middle School grades are learning in Science. I think that at first blogger was a bit of a weird thing for us 8^th graders, but now we are more comfortable with it and I think that we enjoy reading what our peers have to say about our Science class. It is also interesting to see what other people/ students think about the Science we do. Overall Blogger seems to fine and even though some of us had difficulties, we now understand it.

Planets, Dwarf Planets, & More

Today in class, we reviewed the moon's phases, listed all the planets in our solar system, and talked a little bit about dwarf planets.

Some words that were used in today’s class:

equinox- equal day and equal night ( 12h of light and 12 h of darkness)

solstice- longest day (Summer) and shortest day (Winter)

light year- the distance that light travels in one year

electromagnetic spectrum- UV, IR, X-rays, gamma, microwaves, radio waves, and visible light

Today we went over the eight planets in our Solar System. To remember them, a student showed us a pneumonic device.

Our eight planets in our Solar System:

Mercury (My)

Venus (Very)

Earth (Educated)

Mars (Mom)

Jupiter (Just)

Saturn (Sold)

Uranus (Us)

Neptune (Nine)

Below is a picture of all the planets:

Trip through the Solar System video :http://http//www.youtube.com/watch?v=Y72EizrCkKY&feature=fvsr

After "Nine" there should be "Pizzas." "Pizzas" represented the planet Pluto, however now Pluto is not a part of the Planet group, it is now considered a dwarf planet. A dwarf planet has different qualities than planets. Some of those qualities are its size and clear orbit. Pluto is not the only dwarf planet, there are 5 dwarf planets in total. They are:

Pluto

Ceres

Eris

MakeMake

Haumea

Past Pluto, there is the Kuiper Belt, past the Kuiper Belt is the Oort Cloud.

More about the Kuiper Belt & Oort Cloud : http://nineplanets.org/kboc.html

In between Mars and Jupiter is the asteroid belt. The asteroid belt is a space between those planets, filled with loads of asteroids. Asteroids are rocky metallic things that orbit the Sun.

Random facts from Class:

The light from the Sun to Earth takes 8 minutes!

A blue moon is when there are TWO full moons in one month!

The Earth spins counter-clock wise!

The speed of sound is 340.29 m/s!

The speed of light is 300,000 km/s

Our galaxy, the milky way, is 100,000 light years away!

Next scriber - Kamil