General Chemistry - Balancing Equations - Tutorials

Detailed step-by-step tutorial illustrating how to balance a chemical equation.  I think I am beginning to like chemistry. 

Welcome to Chembalancer

The game was fun!  It was a nice, fun way to learn balancing chemical equations.  I think I've finally learned how to balance chemical equations for the first time!  despite having learned them many years back in high school...

Semiconductor of the Week - Silicon

The symbol for silicone is Si, its atomic number is 14.  It is less reactive than carbon. 


Silicon is the eighth most common element in the universe by mass, but very rarely occurs as the pure free element in nature.

Silicon is present in the sun and stars. Silicon makes up 25.7% of the earth's crust by weight, and is the second most abundant element, exceeded only by oxygen. It is found largely as silicon oxides such as sand (silica), quartz, rock crystal, amethyst, agate, flint, jasper and opal.


Silicon has many industrial uses. It is a principal component in microchips.  Silicon is widely used in semiconductors because it remains a semiconductor at higher temperatures and forms a better semiconductor/dielectric interface than any other material.

A mole

Below is my understanding of the mole:

1.  It's a unit of measurement for chemical substances.  It's symbol is mol
2.  Mole is actually derived from the German word "molekul", which means molecule.
3.  The weight of one mole of any chemical listed on the periodic table is equal to its atomic mass.  
4.  One mole = 6.02214179×1023

I also discovered the following piece of interesting information:
October 23 is called "Mole Day".  An informal holiday in honor of the unit among North American chemists.  Date is derived from Avogadro's number and it officially starts at 6:02 AM and ends at 6:02 PM.

Avogadro's Hypothesis

This website helped me to understand more clearly how Avogadro's number was discovered and how Avogadro's principle was totally ignored till many years after this death.  How sad that he lived unrecognized.  But it's a good thing that we attach his name to this miraculous number:  6.02 x 10²³       It's the least we can do to show our respect to the man who helped us to make a giant leap in chemistry.

The check buttons to the questions don't seem to be working though.  

Alkali Earth Metal of the Week - Calcium

The symbol for Calcium is Ca and its atomic number is 20.  Calcium is essential for living organisms, particularly in cell physiology.  It is also a major material used in mineralization of bones and shells.

Calcium has many uses:
- in extraction of other metals, such as uranium
- as an alloying agent used in the production of alloys, eg aluminium alloys, magnesium alloys
- in the making of cements and mortars in construction

Calcium is also a mineral essential for life. We've been told that three glasses of milk per daywill help prevent osteoporosis, the weakening of bones. Yet osteoporosis seems to be on the rise.  However, studies have shown that “The countries with the highest rates of osteoporosis are the ones where people drink the most milk and have the most calcium in their diets. The connection between calcium consumption and bone health is actually very weak, and the connection between dairy consumption and bone health is almost nonexistent.” ( http://health.learninginfo.org/osteoporosis.htm )


Humans are the only mammals in the world who continue to drink milk after they are weaned off and not only do they continue to drink milk, but they drink another mammal's milk!  Something just doesn't seem right here...

Alchemy

Alchemy is an artful method to turn base metals into gold.  For spiritual seekers, it is a way to attain the ultimate wisdom and may be achieve longevity.  To me, the longevity they are seeking is not simply about prolonging physical existence, it's about finding eternal life.  Alchemy is the spiritual seekers' way to gain as much energy as possible, a way to be connected with the divine source of universal energy both within themselves and externally to attain eternal life/nirvana. 

In practice, this is much harder to achieve than it sounds. In ancient China, to practice alchemy, there was a strict requirement for being virtuous.  The requirements for moral character were much higher than those for intelligence and knowledge. The truth of the universe is vast, deep and pure, it's impossible to tap into this truth with an impure, selfish mind.  Alchemy is therefore not just about turning metal into gold, it's also a spiritual quest to nirvana.