Properties of matter

Matter has certain properties. Some of them, such as mass and volume, are common for all substances. Other properties like boiling point, density, solubility, etc... are characteristic to each type of substance. Now, let s see how we can classify them  

Chemical properties are properties that change the nature of matter. Flammability, aciditiy, basicity, and reactivity with water are some examples of chemical properties. When the chemical properties of a substance are altered, it means a chemical change (new substance formed) occurred. 

There are many ways to describe matter. Some things are either big or small. Other things 

Lava is a very hot liquid until it cools. Then, lava becomes a solid rock. 

Mass is the amount of matter in an object or substance. All forms of matter have mass. Solids, gases, and liquids have mass. The more neutrons and protons there are in an atom, the larger its mass will be. An atom of gold has 197 protons and neutrons. An atom of aluminum has only 27 protons and neutrons. This is why gold has a greater mass than aluminum. 

Comparing sizes of objects does not help us to determine mass. This scale shows us that gold has greater mass than aluminum. 

The pull of gravity is different on each of the planets in our solar system. If you weighed 88 lbs (40 kg) on Earth, the table will show you how much you would weigh on the other planets. Your mass would still stay the same. 

Does it contain more than one kind of atom  

EXERCISE 1.1 Distinguishing among Elements, Compounds, and Mixtures 

Because the material is uniform throughout, it is homogeneous. Because its composition differs for the two samples, it cannot be a compound. Instead, it must be a homogeneous mixture. 

Which of the following is the correct description of a cube of material cut from the inside of an apple  

Some properties, such as temperature and melting point, are intensive properties. Intensive properties do not depend on the amount of sample being examined and are particularly useful in chemistry because many intensive properties can be used to identify substances. Extensive properties depend on the amount of sample, with two examples being mass and volume. Extensive properties relate to the amount of substance present. 

Real-World Reading Link Picture a glass of ice water. The ice floats, and you know the ice will eventually melt if left long enough at room temperature. When the water changes from solid to liquid, does the composition of the water also change  

Recall from Chapter 1 that matter with a uniform and unchanging composition is called a substance, also known as a pure substance. Table salt is a pure substance. Another example of a pure substance is pure water. Water is always composed of hydrogen and oxygen. Seawater and tap water, on the other hand, are not pure substances because samples taken from different locations will often have different compositions. That is, the samples will contain different amounts of water, minerals, and other dissolved substances. Substances are important much of your chemistry course will be focused on the composition of substances and how they interact with one another. 

O Reading Check Name and define the common states of matter. 

A liquids volume is constant regardless of the size and shape of the container in which the liquid is held, the volume of the liquid remains the same. Because of the way the particles of a liquid are packed, liquids are virtually incompressible. Like solids, however, liquids tend to expand when they are heated. 

O Reading Check Compare the properties of solids and liquids in terms of their particle arrangements. 

All of the material—the stuff —around us is matter. A substance is matter that has a uniform and unchanging composition. For example, water is a pure substance. No matter where it is found, a sample of water will have the same composition as any other sample of water. 

A physical property of a substance is a characteristic that can be observed and measured without changing the composition of the substance. Words such as hard, soft, shiny, dull, brittle, flexible, heavy (in density), and light (in density) are used to describe physical properties. 

A chemical property describes the ability of a substance to combine with or change into one or more other substances. For example, the ability of iron to form rust when combined with air is a chemical property of iron. The inability of a substance to combine with another substance is also a chemical property. For example, the inability to combine with most other substances is a chemical property of gold. 

Under ordinary conditions, matter exists in three different physical forms called the states of matter—solid, liquid, and gas. Solid matter has a definite shape and a definite volume. A solid is rigid and incompressible, so it keeps a certain shape and cannot be squeezed into a smaller volume. A solid has these properties because the particles that make up the solid are packed closely together and are held in a specific arrangement. 

Liquid matter has a definite volume, like a solid, but flows and takes the shape of its container. A liquid is virtually incompressible because its particles are packed closely together. A liquid flows because the particles are held in no specific arrangement but are free to move past one another. 

M FIGURE 1.9 Classification of matter. All pure matter is classified ultimately as either an element or a compound. 

Answer It is a compound because it has constant composition and can be separated into several elements. 

In a chemical change (also called a chemical reaction), a substance is transformed into a chemically different substance. When hydrogen burns in air, for example, it undergoes a chemical change because it combines with oxygen to form water (T FIGURE 1.10). 

There are three natural states of matter solid, liquid, and gas. Most collections are limited to solids, although the occasional liquid or gas may be included. There may still be bourbon in that Elvis-shaped decanter, mercury in that antique thermometer, or neon in that advertising sign. 

A substance is defined by its chemical composition and internal structure, which in turn define its properties. Knowledge of physical and optical properties is essential for anyone who needs to identify, care for, or describe natural materials in any form. 

The following are some of the basic properties of solid matter. The terms listed here are not applicable to all natural materials. Some are specific to either organic or inorganic materials, and some of them will be used only occasionally. 

Dictionary definitions of chemistry usually include the terms matter, composition, and properties, as in the statement that chemistry is the science that deals with the composition and properties of matter. In this and the next section, we will consider some basic ideas relating to these three terms in hopes of gaining a better understanding of what chemistry is all about. 

Properties are those qualities or attributes that we can use to distinguish one sample of matter from others and, as we consider next, the properties of matter are generally grouped into two broad categories physical and chemical. 

A physical property is one that a sample of matter displays without changing its composition. Thus, we can distinguish between the radish brown solid, copper, and the yellow solid, sulfur, by the physical property of color (Fig. 1-2). 

Sometimes a sample of matter undergoes a change in its physical appearance. In such a physical change, some of the physical properties of the sample may change, but its composition remains unchanged. When liquid water freezes into solid water (ice), it certainly looks different and, in many ways, it is different. Yet the water remains 11.19% hydrogen and 88.81% oxygen by mass. 

In a chemical change, or chemical reaction, one or more kinds of matter are converted to new kinds of matter with different compositions. The key to 

The world we live in is a kaleidoscope of sights, sounds, smells, and tastes. Our senses help us to describe these objects in our lives. For example, the smell of freshly baked cinnamon rolls creates a mouthwatering desire to gobble down a sample. Just as sights, sounds, smells, and tastes form the properties of the objects around us, each substance in chemistry has its own unique properties that allow us to identify it and predict its interactions. 

Do you get excited about news in science and technology Do you like to explain information in a way that others find interesting and understandable Then consider a career as a science writer. 

Science writers keep up-to-date on what is happening in the worid of science and transiate that news so nonscientists can understand it. These writers work for newspapers, magazines, scientific pubiications, teievision stations, and internet news services. Lots of curiosity, as weii as a degree in a science and/or journaiism, is essentiai. 

Miners reiied on the physical property of density to distinguish goid (19 g/cm ) from the worthiess minerais in their sluice pans. The density of pyrite, a worthiess minerai often mistaken for goid, is 5 g/cm.  

Substance Color State at 25°C Melting point (°C) Boiling point (°C) Density (g/cm ) 

Extensive and intensive properties Physical properties can be further described as being one of two types. Extensive properties are dependent upon the amount of substance present. For example, mass, which depends on the amount of substance there is, is an extensive property. Length and volume are also extensive properties. Density, on the other hand, is an example of an intensive property of matter. Intensive properties are independent of the amount of substance present. For example, density of a substance (at constant temperature and pressure) is the same no matter how much substance is present. 

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One of the most significant achievements of the twentieth century is the description of the quantum mechanical laws that govern the properties of matter. It is relatively easy to write down the Hamiltonian for interacting fennions. Obtaining a solution to the problem that is sufficient to make predictions is another matter. 

In equilibrium statistical mechanics, one is concerned with the thennodynamic and other macroscopic properties of matter. The aim is to derive these properties from the laws of molecular dynamics and thus create a link between microscopic molecular motion and thennodynamic behaviour. A typical macroscopic system is composed of a large number A of molecules occupying a volume V which is large compared to that occupied by a molecule ... 

Castleman A W and Mark T D 1986 Cluster ions their formation, properties, and role in eluoidating the properties of matter in the oondensed state Gaseous Ion Chemistry and Mass Spectrometry ed J FI Futrell (New York Wiley)... 

The time is perhaps not yet ripe, however, for introducing this kind of correction into calculations of pore size distribution the analyses, whether based on classical thermodynamics or statistical mechanics are being applied to systems containing relatively small numbers of molecules where, as stressed by Everett and Haynes, the properties of matter must exhibit wide fluctuations. A fuller quantitative assessment of the situation in very fine capillaries must await the development of a thermodynamics of small systems. Meanwhile, enough is known to justify the conclusion that, at the lower end of the mesopore range, the calculated value of r is almost certain to be too low by many per cent. 

Equivalent Weights Acid-base titrations can be used to characterize the chemical and physical properties of matter. One simple example is the determination of the equivalent weighf of acids and bases. In this method, an accurately weighed sample of a pure acid or base is titrated to a well-defined equivalence point using a mono-protic strong acid or strong base. If we assume that the titration involves the transfer of n protons, then the moles of titrant needed to reach the equivalence point is given as... 

There is no discontinuity in volume, among other variables, at the Curie point, but there is a change in temperature coefficient of V, as evidenced by a change in slope. To understand why this is called a second-order transition, we begin by recalling the definitions of some basic physical properties of matter ... 

Equations (10.17) and (10.18) show that both the relative dielectric constant and the refractive index of a substance are measurable properties of matter that quantify the interaction between matter and electric fields of whatever origin. The polarizability is the molecular parameter which is pertinent to this interaction. We shall see in the next section that a also plays an important role in the theory of light scattering. The following example illustrates the use of Eq. (10.17) to evaluate a and considers one aspect of the applicability of this quantity to light scattering. 

During the nineteenth century the growth of thermodynamics and the development of the kinetic theory marked the beginning of an era in which the physical sciences were given a quantitative foundation. In the laboratory, extensive researches were carried out to determine the effects of pressure and temperature on the rates of chemical reactions and to measure the physical properties of matter. Work on the critical properties of carbon dioxide and on the continuity of state by van der Waals provided the stimulus for accurate measurements on the compressibiUty of gases and Hquids at what, in 1885, was a surprisingly high pressure of 300 MPa (- 3,000 atmor 43,500 psi). This pressure was not exceeded until about 1912. 

Thermophysical Properties of Matter, Vol. 4, Thermal Expansion, Plenum Publishing Corp., New York, 1970. 

A. H. Cottrell, The Mechanical Properties of Matter, Robert E. Krieger Publishing Co., Huntington, New York, 1981. 

Touloukian, Y.S., and DeWitt, D.P. (1972), Thermal Radiative Properties of Non-metallic Solids, in Thermophysical Properties of Matter, Plenum, New York, pp. 3a-48a. 

A. H. Cottrell, The Mechanical Properties of Matter, Wiley, 1964, Chap. 9. D. Hull, Introduction to Dislocations, 2nd edition, Pergamon Press, 1975. W. T. Read, Jr., Dislocations in Crystals, McGraw Hill, 1953. 

Since p is a complex number, it may be expressed in terms of the amplitude factor tan P, and the phase factor exp jA or, more commonly, in terms of just P and A. Thus measurements of P and A are related to the properties of matter via Fresnel coefficients derived from the boundary conditions of electromagnetic theory. ... 

As we saw in Chapter 3, the founding text of modern materials science was Frederick Seitz s The Modern Theory of Solids (1940) an updated version of this, also very influential in its day, was Charles Wert and Robb Thomson s Physies of Solids (1964). Alan Cottrell s Theoretical Structural Metallurgy appeared in 1948 (see Chapter 5) although devoted to metals, this book was in many ways a true precursor of materials science texts. Richard Weiss brought out Solid State Physics for Metallurgists in 1963. Several books such as Properties of Matter (1970), by Mendoza and Flowers, were on the borders of physics and materials science. Another key precursor book, still cited today, was Darken and Gurry s book. Physical Chemistry of Metals (1953), followed by Swalin s Thermodynamics of Solids. 

H. Kamerlingh Onnes (Leiden) properties of matter at low temperatures and production of liquid helium. 

Following the general trend of looldng for a molecular description of the properties of matter, self-diffusion in liquids has become a key quantity for interpretation and modeling of transport in liquids [5]. Self-diffusion coefficients can be combined with other data, such as viscosities, electrical conductivities, densities, etc., in order to evaluate and improve solvodynamic models such as the Stokes-Einstein type [6-9]. From temperature-dependent measurements, activation energies can be calculated by the Arrhenius or the Vogel-Tamman-Fulcher equation (VTF), in order to evaluate models that treat the diffusion process similarly to diffusion in the solid state with jump or hole models [1, 2, 7]. 

Click Coached Problems for a self-study module on physical properties of matter. 

In most applications, thermodynamics is concerned with five fundamental properties of matter volume (V), pressure (/ ), temperature (T), internal energy (U) and entropy (5). In addition, three derived properties that are combinations of the fundamental properties are commonly encountered. The derived properties are enthalpy (//). Helmholtz free energy (A) and Gibbs free energy ) ... 

Whi comk to chemistry You are about to embark on an extraordinary voyage that will take you to the center of science. Looking in one direction, toward physics, you will see how the principles of chemistry are based on the behavior of atoms and molecules. Looking in another direction, toward biology, you will see how chemists contribute to an understanding of that most awesome property of matter, life. You will be able to look at an everyday object, see in your mind s eye its composition in terms of atoms, and understand how that composition determines its properties. 

Not all observations are summarized by laws. There are many properties of matter (such as superconductivity, the ability of a few cold solids to conduct electricity without any resistance) that are currently at the forefront of research but are not described by grand laws that embrace hundreds of different compounds. A major current puzzle, which might be resolved in the future either hy finding the appropriate law or by detailed individual computation, is what determines the shapes of big protein molecules. Formulating a law is just one way, not the only way, of summarizing data. 

Chemistry is concerned with the properties of matter, its distinguishing characteristics. A physical property of a substance is a characteristic that we can observe or measure without changing the identity of the substance. For example, a physical property of a sample of water is its mass another is its temperature. Physical properties include characteristics such as melting point (the temperature at which a solid turns into a liquid), hardness, color, state of matter (solid, liquid, or gas), and density. A chemical property refers to the ability of a substance to change into another substance. For example, a chemical property of the gas hydrogen is that it reacts with (burns in) oxygen to produce water a chemical property of the metal zinc is that it reacts with acids to produce hydrogen gas. The rest of the book is concerned primarily with chemical properties here we shall review some important physical properties. 

The members of Group 1 are called the alkali metals. The chemical properties of these elements are unique and strikingly similar from one to another. Nevertheless, there are differences, and the subtlety of some of these differences is the basis of the most subtle property of matter consciousness. Our thinking, which relies on the transmission of signals along neurons, is achieved by the concerted action of sodium and potassium ions and their carefully regulated migration across membranes. So, even to learn about sodium and potassium, we have to make use of them in our brains. 

The three representations that are referred to in this study are (1) macroscopic representations that describe the bulk observable properties of matter, for example, heat energy, pH and colour changes, and the formation of gases and precipitates, (2) submicroscopic (or molecular) representations that provide explanations at the particulate level in which matter is described as being composed of atoms, molecules and ions, and (3) symbolic (or iconic) representations that involve the use of chemical symbols, formulas and equations, as well as molecular structure drawings, models and computer simulations that symbolise matter (Andersson, 1986 Boo, 1998 Johnstone, 1991, 1993 Nakhleh Krajcik, 1994 Treagust Chittleborough, 2001). 

The student conceptions that were displayed could be categorised into three main types, namely (1) confusion between macroscopic and submicroscopic representations, (2) extrapolation of bulk macroscopic properties of matter to the submicroscopic level and (3) corrfusion over the multi-faceted significance of chemical symbols, chemical formulas as well as chemical and ionic equations. Student conceptions held by at least 10% of the students who were involved in the alternative instractional programme were identified. Several examples of student conceptions involving the use of the triplet relationship are discussed in the next section. 

Extrapolation of Macroscopic Properties of Matter to the Submicroscopic Level... 

Ozmen (2004, especially for chemical bonding) and Coll und Treagust (2003, chemistiy of metals) can help to develop a first overview. Numerous authors (e g. Pfund, 1975 Schldpke, 1991 Griffith and Preston, 1992 Mas et al., 1987) describe parallels between students conceptions and historical scientific ideas. Schldpke (1991), for example, points out similarities between students conceptions concerning properties of matter and ideas in alchemist thinking. Lee, Eichinger, Anderson, Berkheimer, and Blakeslee (1993) mentions semblances between the ideas of Aristotle and students conceptions about general aspects of the particulate nature of matter and the horror vacui . 

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