Welcome to my fourth “Science Answers” post! If you have a question, you can ask it in the comments here, or ask it in an email. Or find me on Facebook!
Q: (1) How did scientists find elements in the first place? Could there be more undiscovered elements?
(2) How did scientists create the periodic table?
(3) How do we know that everything is made up of atoms, when atoms are so small that they can’t even reflect light (a necessity for seeing them)?
(asked by Mukesh Garbyal)
Really good questions! I was asked these in a comment on my post “Types of Atoms,” and chose to answer them in a post of their own.
Let’s take this apart. I actually want to address the third part of the question first, since it contains a misconception: atoms can reflect light. Their interaction with light is actually why we can see anything in the world.
Everything we know about space comes from radiation.
Now wait just a moment here. That statement explains how astronomy is such a successful field of science—it’s based entirely on the information we can glean from radiation, after all. But how does that make sense?
I mean, it’s one thing to study radiation. It’s quite another thing to study matter, the “stuff” in the universe. How does one have anything to do with the other?
Well…that’s where atoms come in. Radiation does, in fact, have a lot to do with the “stuff” it comes from. And if it weren’t for that basic principle, astronomy as a science wouldn’t work.
Thankfully for astronomers, it does. So what’s the secret, then? What does radiation have to do with matter? Continue reading
Have you ever seen something like this?
I’m going to venture a wild guess and say you haven’t, since scientists have only recently been able to take this kind of image. I learned about it in my biology class this semester, and the professor said that it was a landmark achievement.
You’re looking at an atom.
Yes, that’s right. You’re looking at a single, microscopic building block of matter.
Let me give you an idea of just how small this is. Millions of the smallest atom in the universe can fit lined across the diameter of a single pinhead.
But I’ll ask you another question. If I showed you an image like the one below, would you immediately think, “atom”? Continue reading
Does this look familiar?
It might, or it might not. If it does, you might recognize it as the periodic table of the elements—more often known as simply the “periodic table.” It’s an ingenious way to organize elements that has worked for scientists for quite some time.
To fully appreciate the ingenuity of the periodic table, I’d have to take you through a few chemistry lessons. Never fear, I have every intention of doing so—later. For now, though, I just want to address enough of the world of atoms to talk about stellar spectra.
That just means the spectrums we get from stars, by the way. (Spectra is plural for spectrum.) And that means…well…we’ll talk about it later. Let’s talk about the different types of atoms first.
Atoms are the building blocks of the universe. Which means there must be different types. But what are they? Continue reading
“The Building Blocks of the Universe.” When you put it that way, atoms sound less like a topic specifically for a chemistry class and more like something astronomers might discuss.
They really are. I’ve got a fantastic reason to include atoms under astronomy, and its name is stellar spectra.
We’ve encountered stellar spectra before in these astronomy posts. When I wrote about the spectrograph, an instrument astronomers use to study data, I talked about spectral lines. I also promised we’d come back to elaborate on that later.
We’re not actually going to talk about the spectrograph in this post. I’m saving that for another time. For now, I’m going to cover atoms in a little more detail.
That way, we’ll have a better understanding of how they interact with light later on—and that will help us understand the spectrograph. Continue reading
This is the periodic table, and it’s pretty much the most important table in all of chemistry.
All the little boxes on this “table” are elements, the simplest form of matter. You literally can’t break these down further. What’s the difference between an element and a substance, you ask?
Okay, well, think of it this way. In my post on matter and its forms, I used water as an example of a substance. Water has its own physical and chemical properties, it’s not a mixture of anything, and no matter how many times you divide it up, you’ll still have the same thing.
But water can be divided up into different things chemically. Continue reading
The easiest way to explain mixtures in chemistry is to talk about food.
Think about mixtures in terms of cooking, and there isn’t much I need to tell you. A salad, like the one pictured above, is a mixture. So is chicken noodle soup. So is…hmm, so is lemonade.
I told you we’d be talking about lemonade soon.
Even air is a mixture—of different gases. Believe it or not, we don’t just breathe in oxygen. In fact, if we breathed in pure oxygen, it would be poisonous. We inhale a little bit of nitrogen, too.
A mixture is—by textbook definition—a physical blend of two or more substances. Continue reading
The simplest approach to chemistry is to start basic.
Not basic as in acids and bases, ha-ha…sorry, bad chemistry joke.
I mean basic as in, what the heck even is chemistry?
I admit that I’m better versed in astronomy than chemistry. I’ve studied chemistry for exactly one year of my life—last year, 12th grade. Astronomy, on the other hand, has been my strong suit and my passion for several years.
For me, these Wednesday posts are like a refresher course. I don’t actually remember everything I’ve learned. Good thing I bought a copy of the textbook.
So, I’ll start simple—because chemistry is the study of breaking complex things down to the simplest bits possible. It’s the opposite of astronomy. Astronomy studies huge, mind-blowing phenomena. Chemistry, on the other hand…is mind-blowingly small.
It’s the study of matter. Continue reading