Month: July 2016

Ion naming convention

Ion naming convention

Ion naming convention

07/22/16

“How do we name ionic chemicals?”

When Chemists started describing elements, they ran into a problem. It turns out that keeping track of which element they are working with is an ion and which is not proved to be very difficult. So , they decided to create a few rules to keep track of everything. Let us their methods with the three cases for cations (positive charge ions), and then move to the three cases for anions and wrap up with the convention for molecular compounds containing both cations and anions.

If the cation in question is a metal who only has one ionic form such as lithium[Li] or potassium[k], then one will simply add ion to the end. For example, lithium[li] would become Lithium ion [Li+], and potassium[K] would become potassium ion [K+].

If the cation is a metal that can have multiple ionic forms, then a roman numeral indicating charge combined with the ion suffix will be added. For example, copper[Cu] could be copper(I)[Cu+] with an ionic charge of +1 or copper(II)[Cu+2] with an ionic charge of +2.

If we are dealing with non-metal compounds then we will have the last syllable be -ium. For example, [H3-O] will be called hydronium, and [NH4] will be called Ammonium.

Now, let us begin with the negatively charged anions. If the anion in question is monoatomic (having only one atom), then we will take the ending of the atom’s name and replace it with the -ide. For example, the anionic form of hydrogen[H] will be hydride[H-], and Oxygen[O] will become Oxide[O-].

If the anion in question is polyatomic (multiple atoms), then we will take the ending of the compound’s name and replace it with the suffix -ite for compounds with a net charge of -2 (For example, CO2- will become chlorite and CO3- will become chlorate). Continuing on, polyatomic atoms that have a -1 charge will have the prefix hypo- attached to the -ite form (For example, CO- will become hypo-chlorite) and ones with a -4 charge will have -per prefix attached to the -ate form (For example, CO4- will become per-chlorate).

If the Anion contains an Hydrogen ion [H+] within the name, then the prefix Hydrogen or Dihydrogen in the case of double will be added. For example, HCO3- will become the hydrogen carbonate ion, and H2PO4- will become dihydrogen phosphate ion

If the molecule in question is multiple forms of the same atom bonded to itself, then you would put a prefix before it’s name (pre- for two, tri- for three, and so on) to represent the atom. For example, O2 becomes peroxide, and O5 is pentaoxide

Now, finally, how do we name the element if they consist of a cation+anion? Well, we simply put the name of the cation first and anion last! For example, [CaCl2] will be Calcium Chloride and [AL(NO3)3] will be aluminum nitrate.

Alkaline Earth metals

Alkaline Earth metals

Alkaline earth metals

07/21/16

“What do Chemists mean when they talk about the Alkaline earth metals?”

To continue with our tour of the periodic table, a group that definitely needs attention is the alkaline earth metals. The alkaline earth metals are the second group on the left of the periodic table. The elements that make up this group include beryllium [Be], magnesium [Mg], calcium [Ca], strontium [Sr], barium [Ba], and radium [Ra]. All of these elements share many peculiar properties, such as the fact that they hold two valence electrons, silver colored and soft, have low melting points, boiling points, and densities, and all of their valence electrons are in the 2s range.

Alkali metals

Alkali metals

Alkali metals

07/20/16

“What are some of the special properties of the first group of elements on the periodic table?”

As a child, you may have looked up at the periodic table, saw that it was organized column by column, and asked why Chemists decided to construct it in that matter? Well, it turns out that each of the columns have been arranged together because they share many qualities with one another! So let’s begin with the first group, the Alkali metals. The alkali metals are the metals that sit on the far left of the periodic table. These elements include  lithium (Li), sodium (Na), potassium (k),cesium (cs), and francium (Fr) , and they all share kindred characteristics. First of all, they have only one valence electron in their outer shell, which makes them highly reactive with other elements. Second of all, when they do react, they usually turn into a positive cation.

How to predict if chemical bonding will be ionic or covalent

How to predict if chemical bonding will be ionic or covalent

How to predict if chemical bonding will be ionic or covalent

Isaac Gendler

07/19/16

“How can we predict if chemical bonding will be  ionic or covalent?”

During one’s study of chemistry, one will come across two distinct forms of chemical bonding, ionic and covalent. However, how can we predict which one the elements will undergo? Chemists have discovered that a simple rule of thumb is that can determine which one is which. If the two elements have significantly different group numbers (such as one one on group 1 or 2 on the periodic table and another on group 5-7) then an ionic bond will take place as a result of the difference of electronegativity. If the two chemical are in a similar group, then a covalent bond will take place.  

Brushless motors

Brushless motors

Brushless motors

07/18/16

“Is it possible to have an electric motor without a brush?”

The workings of most DC motor systems are simple and efficient, but with one serious flaw, their brushing infrastructure.

What does this mean?

Well,lets first look at how a D.C motor works. A circular structure of permanent magnets create a magnetic field, and an electromagnet based central rotor will interact with this magnetic field when current is applied to it. This magnetic field will be able to flip the rotor 180 degrees, by which time the polarity of the electromagnet must change to continue. This is accomplished by a mechanical brush located at the center of the rotor. Even though this brush is absolutely necessary for the electric motor to work, it comes with some large drawbacks. This added machinery effectively limits the speed of the motor, is very prone to wearing out (which makes upkeep much more expensive), and makes the temperature much harder to cool.

The solution? How about turn the whole machine inside out! By placing the electromagnets on the outside and the permanent magnets on the rotor and using a computer system to control everything, the motor will have a momentous increase in power generation. Engineers have termed this type of motor an electric motor.

Synchronous vs induction mechanisms for linear motors

Synchronous vs induction mechanisms for linear motors

Synchronous vs induction mechanisms for linear motors

Isaac Gendler

07/17/16

“What are the benefits and drawbacks between the two different types of linear motors?”

Thanks to the constant ingenuity of humanity, it turns out there is not only one way but actually two ways to design a linear motor! The separate cases are know as the Linear induction motor (in which the changing magnetic field of the primary outpaces the one of the secondary) and a linear synchronous motor (In which the magnetic field field of both the primary and the secondary match-up).

Linear induction motors have numerous advantages. First of all, the construction of such systems have a similar layout to existing electric railway infrastructure, making it easier to integrate into an older system.  The track for the LIM is also very simple, making it easier for vehicles of all different shapes and sizes to be integrated. However, induction based technology has a lower efficiency than not only synchronous motors but normal rotary motors as well! In addition, LIM systems have higher weights, which limits their maximum travel speed and carrying capacity!

Luckily, we have more than one option when deciding to use linear motor technology. Linear synchronous motors use lighter-weight technology, which allows for higher speed and cargo levels. The disadvantages of such systems is that exact data is required for monitoring the magnets (to make sure that they are within sync with the LSMs). This results in a much more complicated design for maintaining the guideway. As each train on the platforms must be individually analyzed, a lower train density ensues. Since LSMs are designed to be completely in sync with the magnets, even very small impingements on the systems could result in drastic consequences.

In summation, Engineers have many choices for what type of linear motors they select.

Lenz’s law

Lenz’s law

Lenz’s law

07/15/16

“What is the relationship between a changing magnetic field and induced voltage?”

Because of Maxwell’s equations, we know that there are fundamental relationships between electricity and magnetism. If we think more in depth about this, wouldn’t it not be too far fetched if there be some some of affect that a changing magnetic field could have on electricity? Well, if the little physicist in you wants to ponder more, then it turns out that this relationship is true. One of the most fundamental physical laws is known as Lenz’s law, which states that a changing magnetic flux causes an induced voltage. For those of you who know calculus, we can state this quantitatively that the time derivative of magnetic flux is equal to the induced EMF

AC motors

AC motors

AC motors

07/15/16

“How can we apply AC electricity to motor technology?”

Motors are undoubtedly one of the most useful inventions by humanity. However, how can we integrate this concept with AC electricity? Well, let’s build such a machine in our mind first. This machine will have two primary parts, a stationary stator and a rotary rotor.  The stator consists of a series of highly permeable steel laminations cast inside a circular frame. Winding will pass through this stator, and when AC current is passed through this winding, an electromagnetic field will be formed. This current will go in three phases, so each starts at a different third of the AC cycle, and because of these three different phases, a constantly rotating magnetic field will be formed. A conducting cage will be housed inside the stator to act as a rotar. Since conductors experience a force when exposed to a constantly changing magnetic field, the rotor will begin to rotate, causing mechanical power to be generated. The Speed of the rotor is called the rotor speed, and the speed of the magnetic field is called the synchronous speed. Due to the laws of physics, the rotor will never be able to catch up to the synchronous speed.

 

Linear motors

Linear motors

Linear motors

07/14/16

“What would happen if you made a machine by unfolding a rotary motor?”

Let’s suppose that we want to move something in a linear direction in a highly efficient manner.  What if we took a rotary motor, and unfolded the shell so it would move in a linear direction? Believe it or not, not only does this work in theory, but it has been accomplished before. Engineers have termed this mechanism a linear motor.

To get the big picture, the linear motor works as follows; A square forcer will include an iron core and a thermal protection device. This forcer will rest on a stator will encase magnets, electric wires, a base, and a shield. A Linear guideway will be placed in between the forcer and the stator to allow for movement of the former. The forcer will be housed in forcer plates, and finally a position encoder will be attached to provide feedback on the position of the linear motor. The forcer moves because the controller will provide a constantly changing current at different times to the windings, which in turn will interact with the conductive rotor, causing a magnetic force on the forcer, which will move the rotor at very high speeds.

Linear motors are very pragmatic for many uses. Linear motors have no wearing parts, which makes them faster to build, have longer life cycles, have more efficient temperature control, have higher velocities, and much less polluting to maintain. Linear motors are often applied for industrial, servomechanism, and transportation purposes. Countries such as Germany, Japan, China, the , and the USA are currently using or considering linear motors for transportation purposes.