Energy Levels, Sublevels and Atomic orbitals

Based from the flame test, Neils Bohr compared the model of an atom with that of the solar system. The nucleus of an atom is comparable to the sun the center of the atom and the energy levels are comparable to the orbits and the electrons are comparable to the planets.   Energy levels of an atom is where the electrons occupy.  Based from the Periodic Table of elements the biggest atom has 7 energy levels.  This principal energy levels of the atom has corresponding energy based from Bohr Theory, and and also composed of different sublevels and with different kind of orbitals.  As the energy level increases the energy required also increases.

 Below is a table showing the different principal energy levels with their corresponding sublevels, orbitals and number of electrons:

As you will notice the number of sublevels are just the same as the number of energy levels, and that the name of the sublevels are also the same as the name of orbitals.  In determining the number of orbitals n² is used, where n represents the energy level and the maximum number of electrons can be determined using 2n², where n is also the number of energy levels.

The sublevels are 1s, 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 5s, 5p, 5d, 5f, and 5g.  The last sublevel the 5g is not yet existing in the modern periodic table  There are also sublevels in 6th and 7th energy levels which will be shown below. These sublevels are not yet arranged according to their energies, the electrons distribution mnemonics found in the periodic table arranged the different sublevels according to increasing energy.

The above electron distribution mnemonics can be used to write electron configuration and is already arranged according to increasing energy.  There is an overlapping in some sublevels, example 4s come first before 3d.  This is the arrangement following the above Mnemonics:

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p

Flame Test

We know that atom is composed of three fundamental particles, the proton, electron and neutron.  And that the protons and neutrons are located inside the nucleus and electrons are found outside the nucleus.  Have you seen fireworks display? What are the colors produced? Yes different colors are produced in fireworks display.  What fundamental particle is responsible for the color of the fireworks display? Its the electrons and every element has its unique color of the flame.

Flame test is used to determine the elements present in a compound, because every element emits unique color of the flame which is used to identify the elements.  Below are some elements with their corresponding flame color.

boron -green
calcium - orange
sodium - yellow orange
potassium - light violet
copper - blue-green
barium - pale green
lithium - red
magnesium - white sparks
iron - yellow sparks
arsenic - blue
cesium - blue
copper (I) - green
strontium - crimson
thallium - pure green

How does the flame color produced?

How does the color of the flame produced?  What happens inside the metal atom?  As the metal atom is heated the electrons outside the nucleus are the ones that receive the  heat, electrons then jump to higher energy level upon absorption of heat.  As the electron jumps to higher energy level, the electron is said to be in the excited state, and in that state the electron becomes unstable, the tendency the electron will go back to lower energy levels emitting the excess energy in the form of light.  And this was the basis of Neil's Bohr Model of an atom.

Chemical Formula

Chemical formula shows the kind and number of atoms present in molecules or ionic compounds. Knowing the formula of a compound, you can determine the number of atoms and kinds of atoms present in a compound.  For example, the formula of water, H₂O, will give you an information that there are 2 atoms of hydrogen and only one atom of oxygen, meaning the ratio of the elements also is shown in chemical formula.

Chemical formula can be molecular formula and empirical formula.  Molecular formula shows the exact number of atoms of each element in a molecule.  Empirical formula shows the simplest ratio of elements in a compound or molecule.

Rules in Writing Chemical Formula 

Compounds can be binary compounds consisting only of 2 elements combined chemically, and ternary compounds composed of 3 or more elements chemically combined.   Example of binary compound is NaCl composed only of  sodium and chlorine; while CaCO₃ is an example of ternary compound composed of calcium, carbon and oxygen elements,

A.  Binary compounds
     In writing the chemical formula of binary compounds you have to follow the rules below:
1.  Identify the monoatomic cation and monoatomic anion that are present in a compound.  Example, magnesium chloride, this compound is composed of magnesium ion and chloride ion or chlorine ion. Start by writing the symbol of cation (positive ion) and followed by the symbol of anion (negative ion).

                Mg⁺²      Cl^-1

 2.  In writing chemical formula, the total charge must be equal to zero.   To balance the charges between the 2 ions above, the best way is to use the "criss cross process", which means that the oxidation number of the cation will be the subscript of the anion, and the oxidation number of  the anion will be the subscript of the cation, disregarding the sign of the numbers.

                  Mg₁⁺²     Cl₂^-1 

Analyzing the charges, magnesium will have +2 charge and the chlorine will have -2, with a total charge equal to 0.

Finalizing the formula, we have:
                  MgCl₂

B. Ternary Compounds
     In ternary compound, it has the same rules as that of binary compound, only that parenthesis is used for polyatomic ions having 2 or more subscript.
1. Identify the monoatomic or polyatomic cations so as the anions. Also write the symbol or fomula of the cation followed by the anion.  For example the compound Iron (III) sulfate, it is composed of iron having +3 oxidation number and sulfate ion (SO₄^-2).
          Fe⁺³  SO₄^-2

2.  The same as that of the binary compound, the charge of the chemical formula of ternary compound must be equal to zero. So, to balance the charges the crisscross process also will be used.   The oxidation of iron which is 3 will be the subscript of sulfate and the oxidation of sulfate  will be the subscript of iron.

          Fe₂⁺³  SO_{4 3}^-2

Analyzing the charges, Fe will have a charge of +6 and sulfate will have -6, with a total charge of 0.

In writing chemical formula, polyatomic ion, although composed of 2 or more elements, just act as one in chemical formula writing, therefore the subscript 3 must not only belong to oxygen but also for sulfur, to do so parenthesis is used, as shown below:

          Fe₂(SO₄)₃

If the subscript of the polyatomic ion is equal to one, it is not written because absence of subscript means one.  On the other hand, parenthesis also should not be written if the subscript is equal to 1.

Since writing chemical formulas involve balancing the charges between the cation and anion, once the charge is already equal, no subscript is added to both cation and anion.  Like for example the compound calcium carbonate, composed of calcium ion and carbonate ion.

         Ca⁺²   CO₃^-2

Since both have the same oxidation number, meaning the charge is already equal, the formula will be

         CaCO₃

Circulatory System

Circulatory system is the life support structure that delivers oxygen and nutrients to the cells of the different parts of the body and also transport waste away from the body.  It is composed of three major parts the heart, blood, and blood vessels.

The three major parts of the circulatory system and their functions:

Heart - pumps blood throughout the body.
Blood - carries oxygen, and nutrients to the different parts of the body.
Blood vessels - carries the blood throughout the body.  Blood vessels are classified as:

• Arteries -carry oxygenated blood away from the heart to the cells, tissues and organs of the body.
• Veins - carry deoxygenated blood back to the heart.
• Capillaries - are very tiny blood vessels that form a connection between arteries and veins.  This is where the exchange of gases occur.

Types of Circulation

1. Pulmonary circulation - is the movement of the blood from the heart to the lungs and back to the heart. 
2. Coronary circulation - is the movement of the blood through the tissues of the heart.
3. Systemic circulation - is the movement of the blood from the heart to the different parts of the body excluding the lungs.

The Human Heart

The heart is a muscle that is the same size of your fist.  It has four chambers, each chamber has corresponding function.  These are the right atrium, left atrium, right ventricle and left ventricle.

The right atrium receives the deoxygenated blood from the different parts of the body; the left atrium, receives the blood from the lungs; the right ventricle, pumps the blood to the lungs; the left ventricle, pumps the blood to the different parts of the body.  

There is a valve between atria and ventricles, to prevent the blood from flowing backwards.  The valves are like one-way doors that keep the blood from moving in one direction.  Valves control movement of blood into the heart chambers and out into aorta and pulmonary artery.

Valves of the Heart

• Tricuspid valve - is located between right atrium and right ventricle
• Pulmonary valve- is located between the right ventricle and pulmonary artery
• Mitral valve - is located between the left atrium and left ventricle
• Aortic valve is located between the left ventricle and the aorta

How the heart works

The right atrium receives the blood from the different parts of the body, and will pass to the right ventricle in which is the once responsible of pumping the blood to the lungs.  From the lungs the blood will again go back to the heart entering in the left atrium and to the left ventricle, and then it will be pump to the different parts of the body, and will then again go back to the heart for another cycle.