Test Review

Hey there,

A few ideas I would like to re-present to you before the test and some misconceptions I have seen over the past few days:
1- Heat is just energy, it is not a type of atom or molecule. It affects molecules by making them move around more and spread out.
2- Atoms are tiny tiny tiny, about .0000000000000000000000007 cm. You cannot see them, but their protons, neutrons, and electrons give them their properties and allow them to bond to other atoms.
3- Chemical reactions don't have to be explosive, even if explosions are more fun. Metal slowly rusting from air and rain is a perfect example. Iron (Fe) turns into Iron Oxide (Fe02), which has new properties compared to normal, plain iron.
4- As any substance is heated, its molecules want to expand and move around more. The molecules do NOT change size or get "liquidy", they just spread out. Gases are the most spread out, and solids are the most closely packed.
5- Mass and Energy are conserved in a chemical reaction. This just means if you start out with 1 pound of carbon and 2 pounds of oxygen, you need to have the same amount after the reaction, even if it wasn't all used. You can't just make matter and energy, you can only move it around.

Matter and you

Hello world (and students),
It has been far too long since my last post! We have now been talking about the little parts of matter for a long time now. Just to put it back in perspective, everything you see and to involves matter! One interesting thing I remembered today while looking at this picture was that everything is interconnected. The way that sodium interacts with the element chlorine is based on its electrons and its size. Without these atoms our brains wouldn't function and our food wouldn't taste very good. The way carbon can make 4 bonds with other atoms makes it the backbone of every protein, fat, and carb that you eat. The way that oxygen craves a few atomic buddies makes water, and gives it the unique properties it has. And all these atoms can be traced back to the big bang 14 billion years ago. Complex atoms like iron, uranium, and Silicon were born from exploding stars. We are one piece in a puzzle of shifting, cooling, changing matter in the long long long history of the universe. You should feel pretty special to be made of 7,000,000,000,000,000,000,000,000,000 atoms. You are breathing the same oxygen that was used in George Washingtons DNA, and you are drinking the same water that some one celled organism absorbed 3 billion years ago as life was just beginning on Earth. You are important, take care of what you have. Science can help us appreciate our place in the world.

Smith