DID YOU KNOW???

Chemistry is a big part of your everyday life. You find chemistry in daily life in the foods you eat, the air you breathe, your soap, your emotions and literally every object you can see or touch. Here's a look at some everyday chemistry.

Is There Really a Chemistry of Love?

I don't think there are any magic love potions that you can use to make someone fall in love, but chemistry does play an important role in how a relationship progresses. First, there's attraction. Nonverbal communication plays a big part in initial attraction and some of this communication may involve pheromones, a form of chemical communication. Did you know that raw lust is characterized by high levels of testosterone? The sweaty palms and pounding heart of infatuation are caused by higher than normal levels of norepinepherine. Meanwhile, the 'high' of being in love is due to a rush of phenylethylamine and dopamine. All is not lost once the honeymoon is over. Lasting love confers chemical benefits in the form of stabilized production of serotonin and oxytocin. Can infidelity be blamed on chemistry? Perhaps in part. Researchers have found that suppression of vasopressin can cause males (voles, anyway) to abandon their love nest and seek new mates. Hey, you gotta have chemistry!

Why Do Onions Make You Cry?

Unless you've avoided cooking, you've probably cut up an onion and experienced the burning and tearing you get from the vapors. When you cut an onion, you break cells, releasing their contents. Amino acid sulfoxides form sulfenic acids. Enzymes that were kept separate now are free to mix with the sulfenic acids to produce propanethiol S-oxide, a volatile sulfur compound that wafts upward toward your eyes. This gas reacts with the water in your tears to form sulfuric acid. The sulfuric acid burns, stimulating your eyes to release more tears to wash the irritant away.

Cooking the onion inactivates the enzyme, so while the smell of cooked onions may be strong, it doesn't burn your eyes. Aside from wearing safety goggles or running a fan, you can keep from crying by refrigerating your onion before cutting it (slows reactions and changes the chemistry inside the onion) or by cutting the onion under water.

The sulfur-containing compounds also leave a characteristic odor on your fingers. You may be able to remove or reduce some of the smell by wiping your fingers on a stainless steel odor eater.

Why Does Ice Float?
There are two parts to the answer for this question. First, let's take a look at why anything floats. Then, let's examine why ice floats on top of liquid water, instead of sinking to the bottom.
Answer: A substance floats if it is less dense, or has less mass per unit volume, than other components in a mixture. For example, if you toss a handful of rocks into a bucket of water, the rocks, which are dense compared to the water, will sink. The water, which is less dense than the rocks, will float. Basically, the rocks push the water out of the way, or displace it. For an object to be able to float, it has to displace a weight of fluid equal to its own weight.

Water reaches its maximum density at 4°C (40°F). As it cools further and freezes into ice, it actually becomes less dense. On the other hand, most substances are most dense in their solid (frozen) state than in their liquid state. Water is different because of hydrogen bonding.

A water molecule is made from one oxygen atom and two hydrogen atoms, strongly joined to each other with covalent bonds. Water molecules are also attracted to each other by weaker chemical bonds (hydrogen bonds) between the positively-charged hydrogen atoms and the negatively-charged oxygen atoms of neighboring water molecules. As water cools below 4°C, the hydrogen bonds adjust to hold the negatively charged oxygen atoms apart. This produces a crystal lattice, which is commonly known as 'ice'.

Ice floats because it is about 9% less dense than liquid water. In other words, ice takes up about 9% more space than water, so a liter of ice weighs less than a liter water. The heavier water displaces the lighter ice, so ice floats to the top. One consequence of this is that lakes and rivers freeze from top to bottom, allowing fish to survive even when the surface of a lake has frozen over. If ice sank, the water would be displaced to the top and exposed to the colder temperature, forcing rivers and lakes to fill with ice and freeze solid.