Nature of substances

No one factor can predict if a person will become addicted to drugs. A combination of factors influences risk for addiction. The more risk factors a person has, the greater the chance that taking drugs can lead to addiction.

Nature of substances

Cogito, 2 pp 10 - Pdf version Modern physics has cast doubt on Newton's idea of particles with definite properties.

Do we have to go back to Aristotle for a new understanding of the ultimate nature of substance? But what are all these substances? What do they have in common which makes them substances? We might first turn to scientists for an answer, to physicists in particular.

A physicist will explain how all kinds of ordinary matter are composed of small atoms, which are composed of electrons, protons, and neutrons. Protons and neutrons are again composed of quarks, he says he believes, but when pressed as to what really are electrons and quarks, he says that he can tell you how they behave, but that he doesn't really know what they are.

We have a feeling that we can't go on looking for smaller and smaller constituents ad infinitum. We don't know for certain if physics has yet reached the stage of looking at these ultimate substances.

Of course, physicists almost always believe they have come to that stage, but that might just be because they haven't yet done the right kind of experiment.

This means that if we want to know what these ultimate substances might be like, we have to turn to philosophy rather than to physics.

Nature of substances

We will then have to be satisfied with general principles rather than particular knowledge, because philosophers can only argue from general considerations about what is possible, and do not provide detailed knowledge about what actually occurs in particular circumstances.

Different scientific theories go along with different philosophical frameworks about what our ultimate substances might be like. The physical theories of the Greeks, of Newton and of modern quantum physics assume different philosophical ideas about substances, and these ideas are not compatible with each other.

Hill of Harvard University outlined the various parts of plants that are essential to an understanding of their nature and uses for humans and animals. It was noted that a protecting encloses the vast majority of plant cells and limiting makeup called the Cell Wall.
Nature's toughest substances decoded Aug Share The amount of energy required to change the state of a substance depends on how strong or weak the bonds between the molecules are.
Definition[ edit ] Colors of a single chemical Nile red in different solvents, under visible and UV light, showing how the chemical interacts dynamically with its solvent environment. A chemical substance may well be defined as "any material with a definite chemical composition" in an introductory general chemistry textbook.
December 4,Rice University An illustration shows a model platelet-matrix composite in the foreground and nacre, one of nature's toughest materials, in the background.

They cannot all be correct! My purpose in this article is to illuminate these different basic ideas, and to see whether we can choose between them. Newton's Corpuscles The idea most people have of ultimate substances is one that derives from Democritus c.

They are the ultimate atoms, since they cannot be broken up. They can fly around in space, and bounce off each other perfectly elastically. It was claimed that all phenomena in nature could be explained in terms of the movements and collisions of the corpuscles. It would have been nice if nature had been so simple.

Newton soon realised that his gravitational attraction could not be explained purely in terms of movements and collisions. In fact, when you think about it, the attractive forces that hold any object together cannot be explained on such terms unless, as the Greeks did, you imagined that atoms had little hooks to hold on to each other.

Later scientists soon realised that the electric and magnetic effects they discovered had no simple explanation in terms of movements and collisions. Boscovich - and Faraday - found that their best explanation was in terms of electric and magnetic fields.

But what is a field? Are fields some kind of substance? If so, are they or are they not composed of the same kind of ultimate substances as ordinary matter? In the corpuscular theory there are in general severe problems when it comes to seeing the exact relation of the corpuscles to their forces of interaction whether gravitational, electric, magnetic, or other.

This is because the corpuscles were assumed to be purely actual and definite in every respect, and hence could never have any such thing as a potential field or a force for interactions.

For potentials and forces are features technically called dispositions which may or may not operate. Remember from your physics that a field potential at a place describes how a test charge would react if placed there.

In other words, they are not sufficiently actual and definite to be given to corpuscles. The gravitational, electric and magnetic forces are however precisely those those properties we want science to explain for us. The problems with them show that we have to go back to philosophical considerations about what kinds of substances there may possibly be.

We ought to reconsider those general principles on which we based our very idea of atomic corpuscles. Let us look at the alternatives that were considered in Newton's time. Descartes and Leibniz The other most popular approaches were those of Descartes -and those of Leibniz - Descartes had imagined that the natural world is made out of res extensa, or extended bodies.

That is, the ultimate individuals are those whose nature is just to be extended, and to occupy volumes in space. The trouble with this alternative is that the problem of substance is further from solution, not nearer. According to Descartes, it is mysterious why the ultimate individuals should have mass or inertia, or should proceed through space at constant velocity unless disturbed.

It is even not clear what is stopping the individuals from penetrating into each other, and hence passing through each other unchanged, as we can easily imagine extended bodies such as two geometric spheres doing this.

But the trouble is that it is now mysterious how the monads, his simple substances, can interact with each other at all.There are dozens of reasons people choose to use drugs, and even more reasons that drug use – or any substance use – may lead to substance abuse and eventually dependency.

Some people are biologically predisposed to substance abuse and dependency, both of which are diagnosable and treatable disorders according to the DSM-IV. 3 a: physical material from which something is made or which has discrete existence. b: matter of particular or definite chemical constitution.

c: something (such as drugs or alcoholic beverages) deemed harmful and usually subject to legal restriction possession of a controlled substance substance abuse.

Addiction is a chronic disease characterized by drug seeking and use that is compulsive, or difficult to control, despite harmful consequences.

The initial decision to take drugs is voluntary for most people, but repeated drug use can lead to brain changes that challenge an addicted person’s self-control and interfere with their ability to.

Related Stories

A chemical substance is a form of matter having constant chemical composition and characteristic properties. It cannot be separated into components by physical separation methods, i.e., without breaking chemical bonds. Chemical substances can be simple substances, chemical compounds, or alloys.

Chemical elements may or may not be included in the definition, depending on expert viewpoint.

Recommended for you

Show transcribed image text In nature, substances often possess a crystalline structure. The basic component of a crystal is the unit cell, such as the rectangular parallelpiped illustrated in.y I B L1 Q Tap image to zoom In the questions that follow, express your answers in terms of the unit vectors i, j, and k, that is, a vector with components V, Vy, and Vz in the x, y, and z directions.

‘Of the secondary substances the species is more a substance than the genus, since it is nearer to the primary substance. For if one is to say of the primary substance what it is, it will be more apt to give the species than the genus.’ (2 b8–11).

Chemistry – The Nature of Substances – EDUCOB