09/04/2019 0 COMMENTS

Molecular Orbital Theory

The Lewis structures, the VSEPR theory and the valence binding method form a powerful combination to describe covalent bonding and molecular structures. The results are satisfactory for most of our purposes. However, sometimes, chemists need […]

02/04/2019 0 COMMENTS


We often use the word “probability“ in ordinary language; so, for example: “It is likely that tomorrow can not come”    When we say these kinds of sentences, we want to express that we are […]

21/03/2019 0 COMMENTS

Elasticity and Fracture

When an object is at rest, we can think that it is not interesting to study because it does not have speed or acceleration and because the forces which are acting on it are zero. […]

04/03/2019 1 COMMENT

Force and Pressure in Fluids

The three common states, or phases, of matter, are solid, liquid, and gaseous. The solid maintains a fixed shape and size; even when a large force is applied, a solid will not change easily in […]

27/02/2019 0 COMMENTS


A succession is an ordered sequence of numbers, such as: A succession of real numbers is an application of the set N (set of natural number excluding zero) in the set R of the real […]

18/01/2019 0 COMMENTS

Pure substances and mixtures

Matter is made up of tiny units called atoms. We currently know that there are 119 different types of atoms, which are the basis of the 119 elements of the periodic table (including “unnunennio” which […]

08/01/2019 0 COMMENTS


When two or more bodies approach each other, internal forces act between them, causing a variation in their linear momentum and in their energy, producing an exchange between them of both magnitudes. In this case, […]

18/12/2018 0 COMMENTS

The chemistry of carbon

Since its beginnings in the 18th and 19th centuries, chemistry has been divided into two main branches: organic chemistry and inorganic chemistry. Organic Chemistry: It was associated with the chemistry of living beings and the […]

07/12/2018 0 COMMENTS


The union of racional and irracional numbers forms a set called real numbers. If we remember the different types of numerical sets, we see that we have: Rational numbers also contain integers numbers that have […]

27/11/2018 0 COMMENTS

The circular movement

The circular movement, also called, of curvilinear trajectory is much more abundant than the rectilinear movement. These are based on an axis of rotation and constant radius, whereby the trajectory is a circumference. Uniform Circular […]

18/11/2018 0 COMMENTS

Changes of states of matter

Matter is everything that surrounds us that has mass and weight, that occupies a place in the space, that is perceptible by one of our senses and that is opposed to changing position, which is, […]

05/11/2018 0 COMMENTS

Empirical and molecular formula

The empirical formula is the simplest expression to represent a chemical compound. It tells us the elements that are present and the minimum proportion in whole numbers between their atoms. This formula is also known […]

05/11/2018 0 COMMENTS

The rectilinear movement

Movement is one of the physical phenomena that we most directly perceive, but the form of that movement depends on the place from which it is observed. It is the so-called “reference system (SR)”.    […]

12/01/2018 0 COMMENTS

Calculation of areas – Definite Integral

Calculation of areas – Definite Integral   Definite Integral of a function is used to calculate the areas of flat regions, which are delimited by curves and straight lines.   Areas of flat regions:   […]

09/01/2018 0 COMMENTS

Gravitational Field, Electric Field and Magnetic Field

  Comparative study between the Gravitational Field, Electric Field and Magnetic Field   GRAVITATIONAL FIELD ELECTRIC FIELD MAGNETIC FIELD   Source Body mass (punctual or mass distribution) Electric charge (punctual or mass distribution) Magnetic field […]

04/08/2016 0 COMMENTS

Organic formulation. Cyclic Hydrocarbons.

Cyclic Hydrocarbons theory   Organic Formulation: Cyclic Hydrocarbons They are closed-chain hydrocarbons. Depending on whether or not they have unsaturations, they are classified as: Saturated monocyclic hydrocarbons (cycloalkanes). Unsaturated monocyclic hydrocarbons (cycloalkenes and cycloalkynes)   […]

04/08/2016 0 COMMENTS

Binomials theory

POLYNOMIALS: Binomials   Binomials are polynomials consist of two monomials separated by a plus (+) or a minus (-) sign.   Binomials operations are:   1.- Binomial squared: is equal to the square of the […]

02/08/2016 1 COMMENT

Organic formulation. Alkynes.

Organic Formulation Theory: Alkynes   Hydrocarbons with triple bonds, Acetylenes or Alkynes They are hydrocarbons having one or more triple bonds between carbon atoms. The general formula for compounds with a triple single bond, is […]

02/08/2016 1 COMMENT

Variations theory

Variations   Variations is to group elements, when it matters the order, we do not take all the items and these can be repeated or not. Thus the variations may be:   Variations without repetition […]

13/07/2016 0 COMMENTS

Permutations Theory

Permutations   Permutations are multiplicative events where the number of possibilities is decreasing and whether it is important the order of a permutation, it is an arrangement of a set of objects in a defined […]

13/07/2016 0 COMMENTS

Organic formulation. Alkenes

Organic Formulation Theory: Alkenes   Hydrocarbons with double bonds, Olefins or Alkenes. They are hydrocarbons having one or more double bonds between the carbon atoms. The general formula with a single double bond is CnH2n. […]

12/07/2016 0 COMMENTS

Organic formulation. Alkanes.

Organic Formulation Theory: Alkanes   Saturated hydrocarbons, paraffins or Alkanes They are called saturated hydrocarbons or alkanes all compounds made of carbon and hydrogen, which are of open-chain and have single bonds.   Straight-chain alkanes. […]

11/07/2016 5 COMMENTS

Divisibility theory

Divisibility   Divisibility is the property of an integer number to be divided by another, resulting an integer number. Where a and b, two integers numbers, we will say that “a” is a multiple of […]

28/06/2016 0 COMMENTS

Combined Operations theory

Combined Operations   We call Combined Operations to those in which several arithmetic operations appear to be solved. To get the right result you need to follow some rules and take into account the priority […]

28/06/2016 2 COMMENTS

Capacitance theory

Capacitance   Capacitance is the ability of a body to store charge in an electric field. Capacitance is also a measure of the amount of electric potential energy stored (or separated) for a given electric […]

14/06/2016 0 COMMENTS

Direct-Current theory

Direct-Current   When it is connected a continuous conductive path, like a wire with a battery terminal, we obtain an electric circuit. The device which receives charging from a battery is not always a wire, […]

14/06/2016 0 COMMENTS

Radicals theory

Radicals   Radicals are expressions with the form: Where n Є N and a Є R; provided that when a is negative, n must be odd. n=index; a=radicand; m=exponent.   A radical can be expressed […]

08/06/2016 1 COMMENT

Chemical Kinetics theory

Chemical Kinetics   Chemical Kinetics studies the speed of chemical processes and determines the factors which influence on it. It aims is to find mathematical expression that relates the speed of a chemical reaction with […]

08/06/2016 0 COMMENTS

Van der Waals Forces

Van der Waals Forces theory   Van der Waals forces, although they don’t form a chemical bond theirselves, they are responsible for the attraction between neutral and saturated molecules, which result in the condensed states […]

08/06/2016 1 COMMENT

Logarithms Theory

Logarithms   Definition of Logarithms: Be a positive real number non-zero and different to 1, and A another positive and non-zero number. It is called the logarithm of the number A in the base a, […]

08/06/2016 1 COMMENT

Fractions theory

Fractions   Definition of Fractions A fraction is the quotient of two integers a and b, which is represented as follows: b -> denominator, indicates the number of parties that has been split the unit. […]

08/06/2016 0 COMMENTS

Periodic System Theory

Periodic System   The current Periodic System is based on the one which was proposed by Mendeleiev with the inherent corrections to Moseley’s law, as it is said, used as sort order atomic number. It […]

08/06/2016 0 COMMENTS

Rotation theory

Rotation   A Rotation is a circular movement of an object around a center (or point) of rotation. A three-dimensional object rotates always around an imaginary line called a rotation axis. A rotation of a […]

17/05/2016 0 COMMENTS

Matrices operations theory

Matrices additions and subtractions theory   The sum of two Matrices (Aij), (Bij) of the same dimension, is another matrix (Rij) of the same dimension and with generic term sij=aij+bij.   Therefore, to be able […]

17/05/2016 0 COMMENTS

Hydrogen Bond Theory

Hydrogen Bond   Many hydrogenated compounds have properties some abnormal that can be interpreted by assuming that amongst its molecules is formed a special type of link, characteristic of hydrogen atoms, called as Hydrogen Bond, […]

16/05/2016 0 COMMENTS

Oscillations theory

Oscillations   Oscillations are the repetitive variation, disturbance or fluctuation over the time measure about a central value or system. A particle oscillates periodically when it moves relative to its equilibrium position. Simple harmonic motion […]

10/05/2016 0 COMMENTS

Calculate the Inverse of a Matrix II

Inverse of a Matrix theory   Inverse of a Matrix Definition method. If the product between two matrices is the identity matrix, then we say that the matrices are “inverse”; because by multiplying them we […]

10/05/2016 0 COMMENTS

Statics theory

Statics   Statics is the branch of mechanics that studies the bodies in condition of balance submitted to the action of forces. Strength is the action that one has on something, either by pulling or […]

10/05/2016 1 COMMENT

Theory about Scientific Notation

Scientific Notation   Scientific Notation helps us to express in an easier way those numerical quantities that are too large or, conversely, too small. It is also known as Exponential Notation and it can be […]

04/05/2016 0 COMMENTS

Covalent Bond theory

Covalent Bond   Covalent Bond (nonmetal-nonmetal):   There are many molecules whose formation can not be explained by the ionic bond, the simplest cases are molecules which are composed of identical atoms, such as H2, […]

04/05/2016 0 COMMENTS

Dynamics theory

Dynamics   Dynamics is the part of physics that describes the time evolution of a physical system in relation to the causes of changes in physical and/or movement state. Dynamics’ aim is to describe factors […]

04/05/2016 0 COMMENTS

Stoichiometry theory

Stoichiometry   Stoichiometry theory Lavoisier’s law of mass conservation: The total mass of the substances involved in chemical transformation remains constant and therefore the sum of the masses of the reactants must be equal to […]

27/04/2016 0 COMMENTS

Powers theory

Powers   Multiplication of Powers with the same base, add exponents   Division of powers with the same base, subtract the exponents   Power of a power, it’s the same base and multiplied the exponents […]

27/04/2016 1 COMMENT

Chemical calculations theory. Dissolutions

Dissolutions   Dissolutions are homogeneous mixtures resulting from the interposition of atoms, molecules or ions from two or more substances, called components, which are involved in varying proportions.   WAYS TO EXPRESS THE CONCENTRATION OF […]

27/04/2016 1 COMMENT

Metallic bonding theory

Metallic bonding   Metallic bonding (metal-metal): This type of bond is given in all pure metals and most alloys.   In a metal, atoms are very close to each other forming what is called a […]

27/04/2016 0 COMMENTS

Kinematics theory

Kinematics   Kinematics is the branch of classical mechanics that describes the motion of bodies (objects) and systems (groups of objects) without consideration of the forces that cause the motion. When we study the motion […]

20/04/2016 0 COMMENTS

Chemical calculations theory. States of matter aggregation.

States of matter aggregation   The matter is present in the nature in three different States of matter aggregation: solid, liquid and gas. Solids have fixed shape and volume. Liquids have fixed volume, but its […]

20/04/2016 0 COMMENTS

Second Principle of Thermodynamics theory

Second Principle of Thermodynamics   Thermodynamics is the branch of physical science concerned with heat and its relation to other forms of energy and work.   It defines macroscopic variables (such as temperature, entropy, and […]

20/04/2016 1 COMMENT

First Principle of Thermodynamics theory

First Principle of Thermodynamics   Thermodynamics is the branch of physical science concerned with heat and its relation to other forms of energy and work; it is studied in processes in which there is transfer […]

18/04/2016 0 COMMENTS

System of Equations theory II

System of Equations   This theory about System of Equations is the continue of the previous post “System of Linear Equations theory”   Gauss method: Gauss method is to transform the given system into an […]

15/04/2016 0 COMMENTS

System of Linear Equations theory

System of Linear Equations Theory: First Degree   The simplest method for solving a System of Linear Equations is to repeatedly eliminate variables.   Steps to take: 1. In the first equation, solve the equation […]

13/04/2016 0 COMMENTS

How to solve an Equation II

Theory of Equations of First Degree   This theory about Equations is the continue of the previous post “How to solve an equation”   Theory of Biquadrate Equations.   To solve a biquadrate equation follow […]

12/04/2016 0 COMMENTS

How to solve an Equation

Theory of Equation of First Degree   To solve an Equation of First Degree follow these steps:   If there are parentheses and/or brackets, they are resolved with the necessary operation.   If there denominators, […]

07/04/2016 0 COMMENTS

Chemical calculations theory

Chemical calculations theory. Matter and its transformations.   Chemical calculations Mole concept: Mol is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kg of […]

07/04/2016 1 COMMENT

Chemical Ionic bonding theory

Ionic bonding   Chemical Ionic bonding (metal-nonmetal):   It is formed by complete transfer of electrons from one to the other, being a metal atom and the other a nonmetal atom. Due to the atoms […]

07/04/2016 0 COMMENTS

Chemical Bond theory

Chemical Bond   The part of chemistry that studies from the theoretical point of view, the Chemical Bond and molecular structure, as well as issues related, it is called theory of chemical bonding and valence […]

01/04/2016 0 COMMENTS

Work and Energy theory

Work and Energy theory   Definition of Work and Energy   Energy is the property that bodies have and allows them to make changes in themselves or in other bodies. His unit in the International […]

31/03/2016 0 COMMENTS

Calculation of a Limit

Limits theory   Finite Limit:   It is said that the function f(x) has for limit L when “x” moves closer to “a”, and is represented by   Infinite limit:     PROPERTIES OF LIMITS: […]

31/03/2016 0 COMMENTS

What is an Electric Field

Electric Field theory   The Electric Field is the region of space in which any cargo located at a point in that region undergoes an action or electrical force due to the presence of a […]

31/03/2016 1 COMMENT

What is a Gravitational Field

Gravitational Field theory   Gravitational Field, Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their masses. The gravitational interaction between two bodies can be expressed by […]

29/03/2016 1 COMMENT

How to solve Integrals

Integrals theory   Integrals are the sum of infinite summands, infinitely small. Given a function f of a real variable x and an interval [a, b] of the real line, the definite integral is defined […]

29/03/2016 0 COMMENTS

How to solve Derivatives

Derivatives theory Derivatives: It is called numerical function to any application of a set E in R For the determination of a function is necessary to know three conditions: The initial set The final set […]

28/03/2016 3 COMMENTS

Calculate the Inverse of a Matrix

Inverse of a Matrix   Inverse of a Matrix (Gauss method) Increase the Matrix with an Identity matrix simply writing the rows of the Identity matrix following the rows of the original Matrix. Make the […]