User:Duplode/On the Physics Handbook Wikibook

From Wikibooks, open books for an open world
Jump to: navigation, search

Let us briefly dissect the first module of the Physics Handbook, which is called Physics Handbook/Matter.

Note


Matter's Definition

Matter is any object that has Mass and Volume exist in Solid , Liquid, Gas .


With better English (matter is a kind of object?) this could be acceptable as a nineteenth century-style classical physics definition, or maybe in an elementary school book. The states of matter are not essential to the definition, though.

Note


Mass is a measurment of matter's material denoted as M and Volume is a measurement of matter's shape denoted as V . The ratio of Mass over Volume indicates the Density of Matter

D = \frac{M}{V}


Again, poor English aside (volume a measurement of shape?), this is an attempt to display the density formula, as it might be reasonable in a handbook. But it is unacceptable to wrap it in a general definition of matter, specially when the author speaks about "Density of Matter" as it was an universal property as fundamental as, say, mass.

Note


Chemical Properties


So this is a chemistry handbook too? Not that it is an unreasonable idea (after all, there is a respected and widely popular Handbook of Chemistry and Physics), but it would be nice to be warned of that beforehand.

Note


All Matter's are made of Chemical Element . All Chemical Elements are made up by the smallest component of material which still have material's property called Atom

Water , H2O


Nonsense. Without bothering you with the details, chemical elements are an abstraction for different types of atoms. At the very least, matter is made of atoms (which are themselves made of protons, electrons, etc.) not of elements, nor can be elements "made up" by atoms. Furthermore, saying that atoms are "the smallest component of material which still have material's property" disregards many things, including the existence of molecules such as the "H2O" the author tried to represent.

Note


Electrical Properties

Experiments of Electricity show that Atom can be divided into sub atomic particles that carry electric charge called Charged Particles .


Neutrons do not carry charge, though...

Note


Charged Particle carries negative electric charge is called Electron . Charged Particle carries positive electric charge is called Proton . Charged Particle carries zero charge is called Neutron .


That disregards, for instance, positrons, which are positive "charged particles" like protons (but which aren't directly part of atomic structure).

Note


Charged Particles ' properties are shown in table below

:{| class="prettytable" width=100%
! Charged Particles !! Mass !! Charge !! Notation 
|-
| Electron || 9.1094 × 10<sup>−31</sup> kg  || −1.602 × 10<sup>−19</sup> C || e<sup>-</sup> 
|-
| Proton || 9.1094 × 10<sup>−31</sup> kg || +1.602 × 10<sup>−19</sup> C || p<sup>+</sup> 
|-
| Neutron || 1.6726 ×10-27 kg  || 0 C || p<sup>0</sup> 
|}


Possibly the first non-objectionable thing in this module.

Note


According to RutherFord's Model All Atom consists of a Nuclues of Proton and Neutron in the center surrounded by circulator orbits of electron. Only Electron in the outermost orbit can participate in reaction .

: Atom = Nucleus of p<sup>+</sup> and n<sup>0</sup> and Orbits of e<sup>-</sup>


Mentioning chemical reactions and valency electrons in this context is totally spurious.

Note


Later on , Bohr make new addition to the Rutherford's Model known as Bohr's Model by saying that every orbit of electron correspond to a distinct Energy level . The outermost orbit has the lowest energy level . When Electrons travel inward from Low Energy to High Energy Light is emitted at a quanta of energy

E_2 - E_1 = h f


Without even discussing whether it is appropriate to discuss historical models of the atom in a handbook, this paragraph is a gross misinterpretation of energy levels in an atom: when the electrons "travel inward" they obviously aren't going from "Low Energy" to "High Energy" - otherwise how could energy be released? The author probably got confused because atomic level energies usually are given taking as referential (zero value) the energy at an infinite distance from the atomic nucleus, and so the energies of the levels are negative and therefore "grow" in absolute value as they get lower. Again, a gross mistake.