Fundamentals of chemistry Intro to the periodic table The periodic table is the arrangements of all known elements into a table
Fundamentals of chemistry
Intro to the periodic table
The periodic table is the arrangements of all known elements into a table , these elements are arranged based off the atomic number and if elements share similar properties to each other.The periodic table is made up of rows and columns which are known as the groups which are the vertical columns and the periods are the horizontal rows.
The lightest elements can be found at the top half of the periodic table and as you get lower down the elements become heavier.
groups have the similarity of elements in the same group the having the same amount of electrons in their outer shell
all elements in the same period have the same amount of energy shells
Metals in the periodic table are found on the left side of the table whereas non-metals are found on the right side of the periodic table.The elements found in between the groups 2 and 13 is where transition metals are.The periodic table holds many different materials with many different properties there are:
non-metals:Some properties of non metals are that they are often poor heat conductors and also poor conductors of electricity.nonmetals come in either the form of solids or gases(other than bromine which comes in the form of a liquid) most nonmetals are non malleable , break relatively easily ,are not ductile and have a low boiling point.They also have low density.
Alkali Metals:Some properties that alkali metals have is that all the alkali metals have one electron found in the outer shell.Like this example lithium ,sodium and potassium are all alkali metals and all have only one electron.More properties would be:
They are highly reactive
Alkali metals have low melting points
They also tarnish easily.
Other elements in the periodic table include:
Rare earth metals
Mendeleev was a chemistry professor who along with Julius Lothar Meyer created the first periodic table which was published in 1869.Mendeleev to classify the periodic table more accurately Mendeleev would sometimes ignore the atomic weight order and switch some elements like iodine and tellurium.Mendeleev is well known for leaving spaces in his periodic table where he predicated undiscovered elements should be placed
This is an atom every atom has a nucleus which is positively charged.The nucleus is made up from three things , protons ,neutrons and electrons.The neutrons have no charge whilst the protons have a positive charge this means the nucleus of an atom will always be positively charged as they have the same amount of protons and neutrons.The number of protons in a element is the element’s atomic number.
Electrons are found on the outer layer of the nucleus’ structure and have a negative charge.When two atoms fuses together this creates a molecule.The electrons on the very outer shell of the atom are called the valence electrons
The atomic number of each element is different and no elements have the same atomic number.Every atom has the same number of both electrons and protons this means the charge in the nucleus will be neutral as they cancel eachother out.
Electrons in a atom are found in the outer shell of the nucleus which are called electron shells.Every electron shell can only carry a certain amount of electrons after the lower energy levels of the shells are filled first the rest of the electrons move to the second energy level.The first shell of the nucleus can only hold a maximum of two electrons on, the second shell can fit up to eight electrons and the third shell can fit up to eighteen electrons
Chemical bonding is a attraction between molecules , atoms or ions that allows the formation of a chemical compound.Chemical bonding is when two or more atoms bond together.
There are four types of chemical bonding and these are:
Ionic bonding is when two atoms bond together one atom loses an electron and the other atom gains that electron that was lost, this then means that one of the ions will be positively charged which is called cation and the other will be negatively charged which is called a anion due to this the atoms attract to each other as the opposite charges attract together which will then form a molecule.ionic bonds often happen as one element has a electronegativity strong enough to be able to steal an electron.
An example of this would be when a sodium atom and chlorine atom bond as sodium loses one electron to form into a sodium ion(Na+) the ion is then transferred to chlorine which then forms a chloride ion (cl-) as these two atoms are now opposite they will then be electrostatically attracted to each other to form an ionic compound.
Another example of ionic bonding would be potassium oxide.For these to both bond the oxygen will need two more electrons however potassium(k) only has one valence electron meaning the oxygen will need two potassium to bond with .
This shows where the electron is being lost and taken to the oxygen element so the two can ionically bond.
This shows the electron being lost from both elements of potassium showing the oxygen will need two electrons to bond together.
Covalent bonding is when two similar atoms bond together by sharing their valence electrons. An example of this would be oxygen has four valence electrons and oxygen has six valence electrons to be able to bond oxygen need two electrons and carbon needs four electrons to form a bond this would mean that the carbon atom must has two double bonds with both of the oxygen atoms.
Polar and nonpolar bonds:
Polar bonds are when electrons are shared unevenly, this is because different elements have different electronegativity which is the ability a atom has in attracting a electron.Non polar bond are when the electrons are evenly shared.polar and nonpolar bonds are a form of covalent bonds.
You can calculate if atoms are going to share electrons evenly by calculating the difference in electronegativity each atom has its own electronegative number on the scale of electronegativity
If the number equals from 0.0 to 0.4 this means the sharing of the electrons will be equal and called non polar , however if the number equals from 0.5 to 1.8 the sharing of electrons will be uneven and will be a polar bond.
An example of this would be hydrogen chloride
Cl has a value of 3.0 and hydrogen has a value of 2.1 if we take away 2.1 from 3.0 this gives us 0.9 meaning the bond will be a polar bond.
Tetrahedral geometry of methane
A methane compound has a tetrahedral geometry.This means that as the carbon has four valence electrons to complete the methanes octet it also needs four hydrogen atoms.
It is called tetrahedral as the hydrogen atoms are at a 109 degree angle meaning the hydrogen atoms are as far apart as they can be making it tetrahedral.
Preparations of standard solutions and titrations in industry
Differences between industry and educational setting(standard solution preparation):
There are many differences between how this is done in a educational environment and an industrial environment some of these are that, when preparing a standard solution and titrations in industry it can be done without the need of supervision and by professionals meaning the data can be recorded much quicker.
Also in industry the data can be collected via machines which can be much faster and read more accurately .unlike educational settings where the information would be recorded manually leaving room for big errors to be made.
Also in educational settings much of the equipment although good equiptment may not be to the best standard and the best quality making the data harder sometimes inaccurate.where as in an industrial setting the equipment used would be top range to ensure the data would be correct.An example of better equipment used would be a automatic titrator which takes the samples weight to carry out the precise titration.
Differences between industry and educational setting(titrartions):
In educational settings the ttration can only be done manually this leaves room for error however in industry the often automate the process which gathers data like volume or weight.
Another tool used in industry would be the karl fischer auto titrator