Tag: Periodic table

Ionization energy

Ionization energy

Ionization energy

10/25/16

“How can we measure the amount of energy needed to remove an electron from an atom?”

From common knowledge, we know that if we want to remove an object, it would require energy. So it would logically follow that if we would want to remove an electron from the orbit of an atom, it would require energy as well. Now since atoms come in a diffuse number of sizes as a result of the different combinations of protons and electrons, how can we find a pattern to quantify which elements require more energy to remove an electron? Well, let’s think about it. As mentioned earlier, each atom will come in a different number of sizes. Furthermore, it can be observed that the larger the size, the more decrepit the hold of the nucleus will be on the orbiting electrons. From this reasoning, we can deduce that the larger the radius, the smaller amount of energy would be required to take an electron. This phenomena is termed Ionization energy, and to observe the pattern for ionization energy, one simply has to remember that since ionization energy is inverse to the size of an element, the further up and right one goes on the periodic table, the stronger the hold of the nucleus on the electrons will be. As a result, elements on the left side of the periodic table tend to be better oxidizers since it does not take too much energy to ionize them, while the opposite is true for elements further to the right side of the periodic table.

Electron affinity

Electron affinity

Electron affinity

10/23/16

“How can we measure the energy used when an electron is added?”

 

We know that the energy of an atom changes when an electron is added. But how can we measure so? Well, we know that electrons are always placed into orbitals. And we know that an element’s oxidation state is contingent upon the numbers of orbitals filled. And on top of that, the more orbital shells are filled, the smaller the radius becomes, therefore magnifying the force. So wouldn’t it make sense that it is easier for an electron if most of the valence shells are filled? Therefore, electrons become easier to add the higher occupancy of orbitals.This makes sense because as we move from left to right, elements tend to become more negative in their reactions. Scientists have termed this principle electron affinity.

Abbreviated electron configuration

Abbreviated electron configuration

Abbreviated electron configuration

10/15/16

“What is a simpler way to present electron configuration?”

 

Electron configuration is one of the most fundamental aspects of chemistry. However, it is also one of the most tedious. Why would you want to write series and series of numbers and letters just to represent one element? Well, how about we look at some patterns in the periodic table to help us out. We know that orbitals are only completed when all of the subshells in that level have been filled, and this phenomena only occurs in non-ionized noble gases. An when we advance past a particular noble gas on the periodic table, the whole naming process will start over again (for example, after helium [He] the second orbital will start,and after neon [Ne] the third will start). Since we would know all of the subshells filled up to that point, how about we just list the subshells that come after the last noble gas? For example, titanium [Ti] will become [Ar] 4s2 3d2. This notation is much easier to read and understand than the old drawn out notation.

 

Well, luckily for us, chemists tend to be a fairly intelligent people, so they have instrumented a system known as abbreviated electron configuration to help us. Abbreviated electron configuration

Lithium

Lithium

Lithium

Isaac Gendler

08/17/16

“What are some special properties of Lithium?”

 

When taking a chemistry class, one will learn about an element known as lithium. Lithium has an atomic number of three, so it contains around three neutrons and is an alkaline metal as a result. The atomic weight of lithium is 6.941, and has a density of 0.534 grams per cubic centimeter. Since Lithium has a melting point of 180.5 degrees Celsius,  and a boiling point of 1342 degrees Celsius, this element is a solid at room temperature. Lithium is light and soft, so soft in fact that it could be cut with a knife. For Astrophysicists, Lithium poses a problem, since the amount of Lithium that has been predicted to have been produced during the big bang is actually three times as high then what is empirically observed in stars!

Actinides

Actinides

Actinides

07/31/16

“What are the actinide elements?”

As we continue throughout our tour of the periodic table, we approach a most virulent group of chemicals known as the actinides. All of the actinides have relatively high density, plasticity, and level of radioactivity. The elements that make up the actinide metals include actinium [Ac], thorium [Th], protactinium [Pr], uranium [U], neptunium [Np], plutonium [Pu], americium [Am], curium [Cu], berkelium [Bk], einsteinium [Es], Fermium [Fm], Mendelevium [Md], nobelium [No], and lawrencium [Lr]

Lanthanides

Lanthanides

Lanthanides

07/30/16

“What are the lanthanide metals?”

Continuing on with our tour of the periodic table, we have come across a series of metals with atomic numbers 58 through 71 called the lanthanides. The lanthanides are bright, silvery, and are so soft that they could be cut with a knife. Lanthanides react with hot water to produce hydrogen gas. Lanthanides used to be called the rare metals, not because they were rare, but because it is very difficult to find the in their pure form. The elements that make up the Lanthanides include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

Reversable reactions

Reversable reactions

Reversible reactions

07/24/16

“Is it possible for atoms to revert to their original state after a chemical reaction?”

 

As we all know, when a series of elements undergo a chemical reaction, the elements and their composition will change as a result. However, is it possible for the products to reverse this change and revert to their original forms? Believe it or not, this is a common process. Products of a reaction can re-react and reform into the reactants! This phenomena is known as a reversible reaction, and the symbol for this process is shown in the picture.

Noble gases

Noble gases

Noble gases

07/28/16

“Are there any elements out their that are nearly completely non-reactive?”

We are about to approach probably one of the most interesting parts of the periodic table, the small but important group known as the noble gases. The nobles gases are very special for one very peculiar fact about them: their outer valence shell is completely filled! This makes them chemically inert, which gives them an extremely nonreactive nature with other elements. Noble gases are called noble gasses because in addition to being  colorless, tasteless, odorless, and non-flammable, they also have a low melting and boiling point, which causes them to be gases at room temperature. The elements that make up the noble gases include helium [He], neon [Ne], argon [Ar], krypton [Kr], and xenon [Xe].

Halogens

Halogens

Halogens

07/27/16

“What does the halogen group do?”

During our tour of the periodic table we encounter a very interesting group in the column XVII called the halogens. When the halogens react with water, they form very strong acidic compounds that can made into salts. Halogens usually have an oxidation number of -1, which makes them some of the most reactive elements in science. In fact, halogens are so reactive that directly ingesting some of them can be fatal to the human body!. The elements that make up the halogens include fluorine [F], chlorine [Cl], bromine [Br], Iodine [I], and astatine [At].