INTRODUCTION
This subject aims, to prepare students of Biotechnology career in the knowledge base for the study of chemistry, thereby unifying previous knowledge to start the academic preparation at the undergraduate level
chemistry as well as other science, involving concepts and definitions that make up a form oral and written communication means a chemical language which must be known.
The concepts of atoms, electrons, protons and neutrons, isotopes, molecules, ions, cations, anions, electrolytes and others are described in this unit, in order to be useful for the understanding of subsequent topics. ATOMS
It is known that the concept atom was established in the V century a. C., by the Greek philosophers Leucippus and Democritus, on the assumption that matter can be divided many times in succession until you reach the limit of a particle whose size makes it impossible to divide it even more, a particle that's called "atoms."
The word atom is of Greek origin that means. At present, the atom can be defined as: a.
"Fundamental unit of the elements that may participate in a chemical reaction." B.
"Minimum mass of an element which can operate in a chemical reaction."
The definition of "atom" not differ much from that expressed by Democritus and later established by John Dalton in 1808, who established the first theory of the atom under the following assumptions:
1. Every element is made of tiny particles called atoms.
2. The atoms of one element are equal in mass and size.
3. Atoms of different elements have different mass and size.
4. The atom can not be created nor destroyed in a chemical reaction.
5. Atoms of different s elements combine to form compounds and do so in a simple numerical relationships and another atom.
6. Two or more atoms of different elements can be combined in different relationships to form more than one type of compound.
Dalton's atomic theory was well accepted in his time, however, the investigations carried out after that time has shown that:
1. Not all atoms of the same element have the same mass, as with isotopes.
2. The atom consists of subatomic particles (electrons, protons and neutrons).
3. Under certain conditions, an atom of an element can be converted to another atom of a different element, like radioactive elements.
Despite these failures, the theory Dalton atomic marked the beginning of studies of the atom and the subsequent development of chemistry.
Moreover, as a result of experimental evidence now known, that the atom consists of at least three fundamental particles: electrons
ü ü ü Neutron Proton
Atoms have a very small core containing Most of the mass of the atom and is composed of protons and neutrons. Electrons are found orbiting the nucleus. ELECTRON
.- It is a subatomic particle that has a negative charge, the absolute mass, calculated for the electron is raised to 9.109x10 -28 grams. Because the electron is the lowest charged particle, is also the unit of electric charge and its representation as the relative burden is "-". PROTON
.- It is a subatomic particle which is located in the atomic nucleus and possessing electric charge, equal in magnitude to the electron (1.602x10 coulombs to -9, but positive. The proton charge is the unit of positive electricity and representation as the relative burden is "+". The absolute mass of the proton is to 1.672x10 -24 grams and is 1836 times greater than the mass of the electron.
Neuton .- It is a subatomic particle which is located in the atomic nucleus and has no load is electrically neutral and its mass is similar to that of the proton.
This subject aims, to prepare students of Biotechnology career in the knowledge base for the study of chemistry, thereby unifying previous knowledge to start the academic preparation at the undergraduate level
chemistry as well as other science, involving concepts and definitions that make up a form oral and written communication means a chemical language which must be known.
The concepts of atoms, electrons, protons and neutrons, isotopes, molecules, ions, cations, anions, electrolytes and others are described in this unit, in order to be useful for the understanding of subsequent topics. ATOMS
It is known that the concept atom was established in the V century a. C., by the Greek philosophers Leucippus and Democritus, on the assumption that matter can be divided many times in succession until you reach the limit of a particle whose size makes it impossible to divide it even more, a particle that's called "atoms."
The word atom is of Greek origin that means
"Fundamental unit of the elements that may participate in a chemical reaction." B.
"Minimum mass of an element which can operate in a chemical reaction."
The definition of "atom" not differ much from that expressed by Democritus and later established by John Dalton in 1808, who established the first theory of the atom under the following assumptions:
1. Every element is made of tiny particles called atoms.
2. The atoms of one element are equal in mass and size.
3. Atoms of different elements have different mass and size.
4. The atom can not be created nor destroyed in a chemical reaction.
5. Atoms of different s elements combine to form compounds and do so in a simple numerical relationships and another atom.
6. Two or more atoms of different elements can be combined in different relationships to form more than one type of compound.
Dalton's atomic theory was well accepted in his time, however, the investigations carried out after that time has shown that:
1. Not all atoms of the same element have the same mass, as with isotopes.
2. The atom consists of subatomic particles (electrons, protons and neutrons).
3. Under certain conditions, an atom of an element can be converted to another atom of a different element, like radioactive elements.
Despite these failures, the theory Dalton atomic marked the beginning of studies of the atom and the subsequent development of chemistry.
Moreover, as a result of experimental evidence now known, that the atom consists of at least three fundamental particles: electrons
ü ü ü Neutron Proton
Atoms have a very small core containing Most of the mass of the atom and is composed of protons and neutrons. Electrons are found orbiting the nucleus. ELECTRON
.- It is a subatomic particle that has a negative charge, the absolute mass, calculated for the electron is raised to 9.109x10 -28 grams. Because the electron is the lowest charged particle, is also the unit of electric charge and its representation as the relative burden is "-". PROTON
.- It is a subatomic particle which is located in the atomic nucleus and possessing electric charge, equal in magnitude to the electron (1.602x10 coulombs to -9, but positive. The proton charge is the unit of positive electricity and representation as the relative burden is "+". The absolute mass of the proton is to 1.672x10 -24 grams and is 1836 times greater than the mass of the electron.
Neuton .- It is a subatomic particle which is located in the atomic nucleus and has no load is electrically neutral and its mass is similar to that of the proton.
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