# CHEMISTRY The good news and the bad news. Its all about building blocks.

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CHEMISTRY The good news and the bad news

Hydrogen Carbon-6 Hydrogen Compounds are two or more elements that share electrons or have taken or given electrons away.

Atoms combine to form compounds in simple ratios, such as 1:1, 1:2, 2:2, 1:3, and so forth.

Chemical Equations are simple. 2H 2 + O 2 2H 2 O

Ba(OH) 2. 8H 2 O(s ) + 2 NH 4 SCN(s ) --> Ba(SCN) 2 (s ) + 10 H 2 O(l ) + 2 NH 3 (g ) Ba(OH) 2(aq) + CaSO 4(aq) BaSO 4(s) + Ca(OH) 2(aq) Ca O O O O S Ba O H O H

Good news: Your car rolled off the pier but didnt fall into the water. Bad news: The damage to the yacht is more than the value of the car.

Imagine counting grains of sand. Not easy but not impossible. Now imagine trying to count grains of sand that are 2,000 miles away. Quite impossible even with the worlds best telescope. Well this is the challenge in counting atoms. Counting atoms from 1 foot away is the same as counting grains of sand 2,000 miles away.

Chemical Equations are simple. 2H 2 + O 2 2H 2 O Chemical equations are quite easy. Here we count out 4 hydrogens and 2 oxygen atoms and we can make two water molecules. But how many hydrogens and oxygens would we count out to make enough water to fill a one liter bottle of water?

Imagine the number of grains of sand in a handful of sand: thousands or maybe a million? It would be difficult to count that many. Now imagine the number of grains of sand that would be present if we covered all of the Earth (land and sea) 10 miles deep of sand. That number of grains of sands is the same number of water molecules needed to fill a 1 liter bottle.

The numbers under the element names are the relative weights. However, if you consider one mole of the element (6 x 10 23 atoms) then these numbers are read as grams.

Bridge between mass and number

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