51 posts tagged chemistry
Want to do chemistry experiments while you wait for the bus? Um, who doesn’t. Download this free virtual chemistry set.
Explore the story behind a site in Queens that may become the city’s next Superfund site.
Awesome radiochemistry story.
We could use this at my house. My son had to spit out his chocolate milk at the dinner table the other night. #supermom
He doesn’t know exactly what time is, but he can tell you exactly what a second is: 9192631770 oscillations of an undisturbed Cs atom. Wonderful video.
February is Black History Month. Let’s take time to celebrate the work of Lewis Phectic Haslett an African American inventor who in 1849 received a patent for his Inhaler or Lung Protector, the predecessor to the modern gas mask. Lewis P. Haslett’s simple device lead the way to the more technologically advanced masks used during the two World Wars to protect soldiers and their horses from poison gas attacks. This field manual titled Defense Against Chemical Attack published in 1940 by the War Department shows soldiers the correct way to wear a mask and how to put a mask on your war horse.
Make sure you have secured your own mask before helping your horse with its mask.
A look at some of the chemical elements present in a smartphone, and an explanation of the components their compounds are used for.
You can read more and download the A3 PDF here.
Purchase A2, A1 and A0 poster sizes here.
Each of these tubes is filled with a pure elemental gas* before being excited with 20,000 V. This causes the electrons in the atoms to jump to higher energy states which then emit light when they relax back down.
The light emissions have been diffracted here to show the individual wavelength components, each of which represent the jumps electrons in a particular element can make.
MInd-blowing! What a great way to visualize atomic spectroscopy!
A colleague said to me recently, “…and that is why you shouldn’t use shampoo that contains sulfate.” As you can see, I wasn’t paying attention. All the supporting evidence for this statement was bestowed while I was writing a grocery list, or determining my last gym visit or considering any one of the dozen things that go through my mind on a given day. What were we dealing with? Where were we on the spectrum of concern? Does sulfate in my shampoo cause mutations in my unborn child or does sulfate in my shampoo make it impossible to get any body out of my hairstyle? I was too embarrassed to admit my lapse in concentration to ask. To save face it was easier to just go “sulfate-free.”
We are free freaks. Fat-free, sugar-free, gluten-free, the words seep into our psyche and gull us into believing we are getting something for nothing. It is a great marketing ploy. We fall for it all the time. (The only exception being caffeine-free. Who the hell wants that?) But at what cost? What does all this free seeking get us? Anxiety, not much more.
Before I knew it I was scanning for “sulfate-free” in the hair care isle. It was not hard to find the preferred product, sulfate-free was everywhere. I took it home with a sigh of relief that I found out about this before it was too late. I was righteous, I was keeping sulfates off my head. Wait, why was I keeping sulfates off my head?
If you are familiar with a little chemistry you might recall that a sulfate is a cluster of atoms (one sulfur and four oxygens) with a charge that attracts it to other charged atoms. In shampoo the sulfate in question is sodium lauryl sulfate. This molecule has the charged sulfate at one end and a long, waxy tail at the other which allows it to remove grease and gives shampoo lather.
I am rather fond of sodium lauryl sulfate because I have an oily head. If I showed up at your house after not washing my hair for two days you would think it was pouring outside. My hair would look soaking wet. I can pump out some serious scalp grease. It’s gross. And don’t try to tell me my head creates oils because I wash it too much. I tested the limits of necessary hygienic practices on a number of lazy occasions in college. I can go no more than a day and a half without a good head washing.
Now, if you look for information on the web regarding why sulfates are so hated. You find no good reason. The Environmental Working Group ranks sulfates as low risk. Articles touting the termination of sulfate shampoos admit that there is no safety risk and no real reason to change. This Huffington Post article titled, “Why You Need To Check Your Shampoo Label, Now” ends:
While the benefits seem unclear, my philosophy with sulfate-free shampoo has been, “Hey, it can’t hurt. Right?”
But it does hurt, it hurts tremendously. This mentality perpetuates fear and clouds our judgement in determining a true threat.
The author of this story confesses that she started using sulfate-free shampoo because of media pressure, meaning advertising pressure. If Eva Longoria tells you sulfates are bad you buy sulfate-free shampoo. (I mean, she does have great hair.)
We accept a lot of risk in life. We eat too much, we drink too much, we ride our bikes among the traffic of a crowded city street. But, the risk of shampooing is too great? We are convinced of carcinogens and mutagens lurking in our beauty products. We are obsessed with revealing a conspiracy by the beauty industry to force us all to wear leaded lipstick and mercuryed mascara. Because as we know manufacturers don’t always have our best interests at heart. Sometimes advertisers just tell us what we want to hear to sell us their products. Our mistrust of industry has allowed our fear of chemicals to breed out of control. And now our chemophobia is being used to advertise to us.
We have been played. Two years after the bunk-proven hype over the adverse effects of sodium laurel sulfate more and more beauty companies are marketing sulfate-free products. The rumor is still circulating and has finally reached a tipping point where it can be taken advantage of to sell more shampoo.
I have girlfriends who only need to wash their hair every couple days. I am so envious. They are most often curly haired friends with drier scalps. Understandably, they feel differently about sodium laurel sulfate than I do. Choosing sulfate-free shampoo is a preference, like preferring the feel of your skin after bathing with Lever 2000 rather than Dove. If you like it, fine, buy it. But don’t let advertisers convince you that spending more for sulfate-free will make you safer (or make your hair color last longer – there is no proof of that either). It is just a marketing gimmick.
You are probably like me. Your mind is filled with a dozen different things. You have to get to the gym and you need to write a grocery list, but take the time to assess the validity of a threat and don’t let your fears reign uncontrolled.
This blog is only intended to provide snippets from a vastly complex chemistry world. I don’t review journal articles here or discuss the validity of the data published therein. My lack of doing so should not be interpreted as nescience. I just prefer to keep it light.
I admire bloggers who evaluate the ruggedness of published data. A blogger who calls out the editor-in-cheif of a scientific journal for stating that a blog is an inappropriate place to question scientific findings? Well, that is going to earn my lifelong fandom, especially with such an expertly written retort.
Last week the editorial board of ACS Nano published their thoughts on how scientific misconduct should be handled. They feel it is inappropriate for issues of misconduct to be taken up in a public form such as a blog or on Twitter. ChemBark fired back:
Your assertion that commenting on papers is a “privilege” smacks of the elitist, opaque, closed-door, Old-Boys’-Club approach that many lament has become standard operating procedure in too many areas of chemistry. Many young chemists decry that success in our field is not so much about what you do, but whom you know. Blogs are helping to level the playing field by putting users on equal terms and democratizing the flow of information. In order for any self-governing and self-policing body to operate effectively, members of the community must stay informed about important issues they face. There can be nothing more important to chemistry than the integrity of our data; it is the foundation on which our knowledge is built.
I recommend that you read ChemBark’s Response to ACS Nano Editorial Reporting on Misconduct in its entirety.