Physical Properties of Matter PDF

## Properties of Matter When you choose your clothes, your lunch, or your shampoo, you are making choices based on the properties of matter. Considering how important these properties are to our daily lives, it's not surprising that people have always been curious about matter and how it changes. T...

## Properties of Matter When you choose your clothes, your lunch, or your shampoo, you are making choices based on the properties of matter. Considering how important these properties are to our daily lives, it's not surprising that people have always been curious about matter and how it changes. Through observation, scientists have found it useful to categorize properties as physical or chemical. ### Physical Properties When you observe matter - whether you see it, touch it, hear it, smell it, or taste it - you are observing its characteristics, called physical properties. A physical property is a characteristic or description of a substance that may help to identify it. Unlike a chemical property, a physical property does not involve a substance becoming a new substance. For instance, colour is a physical property. A substance simply has a certain colour: its colour has no relationship to the substance's ability to change into new substances. | Property | Describing the Property | | --------------- | -------------------------------------------------------------------------------------------------- | | Colour | Is it black, white, colourless, red, blue, greenish-yellow...? | | Texture | Is it fine, coarse, smooth, gritty...? | | Odour | Is it odourless, spicy, sharp, burnt...? | | Lustre | Is it shiny, dull...? | | Clarity | Is it clear, cloudy, opaque...? | | Taste | Is it sweet, sour, salty, bitter...? | Some physical properties are summarized in the table above. Pick one of the materials shown in the image above and describe it, mentioning all of the properties listed in the table. There are other physical properties you might choose to describe. Simple tests and measurements can aid your senses in observing these properties. ### The States of Matter One of the physical properties of matter is its state - whether it is solid, liquid, or gas at room temperature. | Example | Solid | Liquid | Gas | | ------- | ------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------- | | Shape | Definite: has a fixed (unchanging) shape. | Indefinite: always takes the shape of its container. | Indefinite: always takes the shape of its container. | | Volume | Definite: has a fixed volume. | Definite: has a fixed volume. | Indefinite: always fills the entire container. | | | | | | ### Hardness Because they are harder than glass, diamonds are used to cut glass. Hardness is a measure of the resistance of a solid to being scratched or dented. A harder material will scratch or dent a softer one. For instance, a diamond stylus is used to cut a large sheet of glass into different sizes. Rank the following substances by hardness: steel nails, chalk, glass, diamond. ### Malleability Gold can be hammered into thin sheets, so it is said to be malleable. If a solid is malleable, it can be hammered or bent into different shapes. Aluminum foil is malleable, which makes it useful for wrapping food as it cooks. Many materials, glass for example, are not malleable. Instead of flattening out when hammered, they shatter. Brittle objects shatter easily. ### Ductility One of the reasons copper is used for electrical wiring is that it can be drawn out into long, thin wires. If a solid is ductile, it can be pulled into wires. What other materials can you think of, besides copper, that are ductile? ### Melting and Boiling Points The temperatures at which substances change state are characteristic physical properties. For example, under controlled conditions, water always changes from solid ice to liquid water at 0°C - its melting point is 0°C. Similarly, the boiling point of water, when it changes from liquid to vapour, is 100°C. ### Crystal Form Solids can exist in different forms. Crystals are the solid forms of many minerals in which you can see a definite structure of cubes or blocks with a regular pattern. For example, when you look closely at salt crystals, you can see that they are tiny cubes. ### Solubility When salt and pepper are added to water, the salt dissolves but the pepper does not. Solubility is the ability of a substance to dissolve in a solvent such as water. Salt is described as soluble and pepper as insoluble. Drink mixes, for example, contain powdered substances that are soluble in water. ### Viscosity Maple syrup is "thicker" than water - it flows more slowly than water when you pour it. Viscosity refers to how easily a liquid flows: the thicker the liquid, the more viscous it is. ### Density When people describe lead as "heavier" than feathers, what they really mean is that lead is more dense than feathers. Density is the amount of matter per unit volume of that matter. This is usually expressed in kilograms per cubic metre (kg/m3) or grams per cubic centimetre (g/cm³). For example, the density of water is 1.0 g/cm³. (It can also be expressed as g/mL and g/L.) ### Chemical Properties In nature, substances often combine or react with each other. When one substance can interact with another, that characteristic behaviour can be called a chemical property. For example, dynamite explodes when exposed to a flame because the dynamite combines with oxygen in the air. This reaction produces new substances. A chemical property describes the behaviour of a substance as it becomes a new substance. ### Combustibility Combustibility is a property that describes the ability of a substance to react with oxygen to produce carbon dioxide, water, and energy. When a flame is brought close to a mixture of gasoline and air, the gasoline ignites and burns. However, water not only does not burn, but can be used to put out some fires. If a substance is combustible or flammable, it will burn when exposed to a flame. A substance that will not burn is described as nonflammable. What other materials can you think of that are combustible? ### Reaction with Acid When magnesium metal is added to acid, it produces bubbles of gas and the metal quickly disappears. However, when gold is added to acid, no visible change occurs. The ability of a substance to react with acid is a chemical property. For example, geologists use acid to test samples of rock. A chemical property of limestone is that it reacts with acid to produce bubbles of gas. ### Using the Properties of Matter Matter can be grouped as metals and nonmetals. Metals are suitable for different uses because of their special properties. Metals have been used by people for thousands of years: first copper, then bronze, iron, and steel. Now, many different mixtures of metals, called alloys, are used. Whatever the purpose, whether for airplane parts, the bottoms of cooking pots, or braces for teeth, the metal chosen has properties useful for the job. The metals used in the braces in the image above, for instance, must have specific chemical properties: they must not react with saliva or chemicals in food. They must also have specific physical properties. Some of these are shown in the table below. | Metal | Stiffness | Springiness | How easily does it bend? | How easy is it to join? | | --------------- | -------- | ----------- | ------------------------ | ------------------------- | | Stainless steel | High | Good | Fair | Fair | | Gold alloy | Medium | Fair | Fair | Easy | | Nickel/Titanium alloy | Low | Excellent | Poor | Difficult |