Periodic Table: Classifications - Online Tutor, Practice Problems & Exam Prep

Elements on the periodic table are categorized into three main classifications: metals, nonmetals, and metalloids. Metals, which constitute the majority of elements, are characterized by their luster, good electrical conductivity, opacity, and malleability. Nonmetals, on the other hand, typically exhibit opposite traits to metals: they are dull, poor conductors, can be transparent, and are brittle. Metalloids, or semiconductors, display properties of both metals and nonmetals and are situated along an imaginary staircase from boron to astatine, with germanium and antimony just below. Silicon, a metalloid, is particularly noteworthy for its use in technology, such as in silicon chips found in computers and phones, highlighting the real-world applications of these chemical classifications. Understanding the distinct properties of these classifications is essential for grasping the behavior of elements and their applications in various fields.

Periodic Table: Classifications

When observing the elements of the periodic table, realize that they can be separated into three classifications. Now here the first classification has to do with all of the elements that are marked as red, and as you can see, a majority of the elements of the periodic table are red. Now before we actually talk about these elements, realize here that these last two rows, they're actually found in between here. So from LA, we actually go to CE all the way to Lu and then come back around to HF. And then after AC, we go to TH and then we go all the way down to LR and then back to RF.

Typically, this row is taken out of the periodic table just to make it look better and more organized. But realize that these two last rows here on the bottom, they're actually within the periodic table. They just pull it out for appearance sake. Now these elements in red are called metals. So all these elements in red are metals. Next we're going to see that we have the elements in blue. So H over here which stands for hydrogen is all by itself. But then all the other blue ones are found on the far right here. So these elements that are on the right side of the periodic table majority wise, they are our nonmetals.

And then finally we have those in green. Now to help us remember where those in green are, imagine that there is an invisible staircase. Now whatever periodic table that you might be using as a sheet, try to color in this staircase that's in dark black lines here on our example of the periodic table. It'll help you remember where these elements in green are located. So there's this invisible staircase starting from B, and it goes all the way to AT. OK, so these are on the staircase, these element, these five elements. Then below the staircase are these two elements GE and SB. So in total we have seven of these green elements.

These green elements are called our metalloids. So just remember we have elements of the periodic table. They can be thrown into three classifications, metals, nonmetals, and metalloids. Now that we know these three classifications, let's continue onward and let's talk a little bit more about each one.

Periodic Table: Classifications

Now the metals represent the largest classification, 4 elements on the periodic table. We can see a lot more elements in red than in either blue or green, so they greatly outnumber the nonmetals and metalloids. Now with these metals come metallic properties and these metallic properties can be explained through physical properties.

For the first physical property of a metal, we have here this piece of metal and what we're trying to convey this image is that metals possess a luster. When we're talking about luster, we're talking about how shiny they are. Metals tend to be extremely shiny. For the next one, we have two wires and between them we have electricity. What this is trying to tell us is that metals are conductors, good conductors. So we're talking about their conductivity.

When referred to conductivity, we're talking about how we're able to run a current of electricity through any typical metal. Later on we'll learn about why that is when it comes to the surface of metals, but for now, just realize that metals are good conductors of electricity. For the next one, we're going to say that metals are opaque. Opaque just means that you cannot see through them. They're not transparent.

And then finally, another great physical property for metals is that they are malleable. Now if we're talking about malleability, that means that we can hammer them into different shapes or into thin sheets without them breaking apart. OK, so if you've seen like renaissance movies, night movies, you might see the blacksmith and they're hammering away at a sheet of metal. That can only happen with metals. Metals are highly malleable. You can flatten them into thin sheets without having to worry about them crumbling and falling apart.

So again, when it comes to metals, they represent the largest classification and these are the most important physical properties associated with them. Now that we've looked at metals, let's move on to the other classifications of the periodic table.

Periodic Table: Classifications Example 1

So here in this example question it says which of the following elements has physical properties most similar to barium O. We have carbon which is represented by the symbol C, Calcium which is CA, Arsenic which is as Xenon which is Xe and chlorine which is CL. Now in order to understand which one has physical properties similar to barium, we have to know what the classification of barium is. Is barium of metal a nonmetal or a metalloid?

So if we go up here, we've highlighted the element barium in black and then the other five choices in blue. We can see here that barium is shaded red. So barium represents a metal. Therefore we're looking for another element that is a metal because then they would share similar physical properties such as opaqueness, opaqueness, malleability, conductivity, etcetera.

Now, calcium looks like the only other one that's red, right? Calcium is our metal. Arsenic is a metalloid because it's green. Carbon, chlorine and xenon are nonmetals because they're shaded blue. So coming back down to our question, we see that calcium is our answer. So be with be would be the correct choice.

So just remember when they're giving you an element and asking you to determine which one has similar physical properties, look for the classification of the element. Is it a metal, a nonmetal or metalloid? Use that to guide you to the right answer.

Periodic Table: Classifications

So nonmetals represent the second largest classification for elements, so they're the ones shaded in blue like we set up above. Now, a key way to remember the physical properties of nonmetals is in comparing them to metals. Just remember here that nonmetals tend to have the opposite trend of metals when it comes to their physical properties.

Metals have a luster, they're shiny. Nonmetals are dull. Metals are good conductors, but nonmetals are poor conductors. Metals are opaque because they're not see through, but nonmetal. Some of them are transparent and see through. And then finally, we said that metals have a malleability where we can hammer them without them falling apart.

The opposite of being malleable is being brittle. If you were trying to hammer some nonmetals, they would literally crumble in your hands. So just remember, if you can remember the physical properties of metals, nonmetals are basically the opposite trend.

Periodic Table: Classifications

Now we've finally reached our third classification, the metalloids. Now the metalloids, we're going to say they have characteristics of both metals and nonmetals. And because of this, we call them semi metals or semiconductors. Now we're going to say here that the metalloids lie on an imaginary staircase starting from boron which is B to acetene which is at.

So if we come back up here to our periodic table, remember those in green represent our metalloids. So from boron all the way down to ask the team, they lie on the staircase, above the staircase, and then below the staircase we have GE, which is germanium and B which is antimony. So here we have 7 metalloids. We're going to say here that they act as a border with the metals lying to the left and most of the nonmetals lying to the right.

Remember on the periodic table, hydrogen was here in the top left corner, but then all the rest of the nonmetals were here on the right side. OK, so most of the nonmetals are found on the right side and except for hydrogen which is on the far left over there. Now here it says which of the following is a metalloid for this example question. So out of the choices that we saw up above, go back up, we have what we have boron, silicon, arsenic, tellurium, acetene, germanium, and antimony.

So these are the names for these different types of metalloids. Again, we'll get to names and symbols later on, but realize these are our seven metalloids now. Based on our options only A, we can see all the choices. So we have A as the only option because here we have BRB and C The other four are not metalloids. Now SI stands for silicon. You might have heard of that term when it comes to Silicon Valley.

So we know that Silicon Valley exists in California. It's a hub for a major tech companies in the country. So it's a place of innovation and technology. But Silicon Valley isn't named after those tech companies. In actuality, it's named after original settlers there who were developing silicon chips. So that's where the name Silicon Valley comes from.

Now, these silicon chips are incredibly important because they're found in so many of our technology. They're found within our computers, our laptops, even our phones. And the reason for this is because silicon is a metalloid, it works as a semi metal or semiconductor. So it's the ideal type of element that can function properly within all of these pieces of technology.

So again you might have heard of Silicon Valley, you definitely have heard of different tech companies, you know what microchips are. So this is real day applications that are based in chemistry and that's going to happen from time to time. You might think something is boring, but then realize that oh it has a real world use that you benefit from every day. So just remember when it comes to the classifications of the periodic table, we have our metals, our non metals and of course our betalloids.

Here’s what students ask on this topic:

Who first published the classification of the elements that is the basis of our periodic table?

The classification of the elements that serves as the basis for our modern periodic table was first published by Dmitri Mendeleev in 1869. Mendeleev was a Russian chemist and inventor who formulated the Periodic Law, created his own version of the periodic table of elements, and used it to correct the properties of some already discovered elements and also to predict the properties of elements yet to be discovered. While there were other scientists, like Lothar Meyer, who were working on similar concepts around the same time, Mendeleev's table was the first to gain widespread recognition and has since been refined to form the current periodic table. Mendeleev's periodic table arranged elements by increasing atomic weight, which is similar to the modern arrangement by atomic number, and it showed recurring ('periodic') trends in the properties of the elements.

Most elements on the periodic table fit into what classification?

Most elements on the periodic table fit into the classification of metals. Metals are located on the left side and in the center of the periodic table, including the transition metals. They are characterized by their ability to conduct heat and electricity, their malleability (they can be hammered into thin sheets), ductility (they can be drawn into wires), and they often have a shiny luster. Metals typically lose electrons during chemical reactions, which is known as oxidation. This large group includes familiar elements like iron, copper, silver, and gold, as well as alkali metals like sodium and potassium, alkaline earth metals like calcium and magnesium, and the transition metals like nickel and platinum.

Looking at the periodic table, which classification has the greatest number of elements?

The classification on the periodic table with the greatest number of elements is the metals. Metals are located on the left side and in the middle of the periodic table, extending from groups 1 (alkali metals) and 2 (alkaline earth metals) through the transition metals, which include groups 3 through 12, and into the lanthanides and actinides, which are the two rows located below the main body of the table. These elements are characterized by their ability to conduct heat and electricity, their malleability, ductility, and typically a shiny appearance. Metals make up the vast majority of the periodic table, with only a small fraction of elements classified as nonmetals or metalloids.