Matter : Property and Changes A

What is Matter? Chemistry is the study of matter and matter is everything that has mass and volume, anything that takes up space. It is everything around you whether you see it or not. Ex. Your notes have matter and so does the air you breathe.

Properties of Matter There are two types of properties of matter. Physical Chemical

Physical Properties Physical Properties – is a characteristic that can be observed or measured without having to change the what the substance is made of. Substance – matter that has a uniform and unchanging composition; a.k.a. pure substance

Physical Properties Characteristics: Softness Color Melting Point & Boiling Point Density Odor Taste

Example The physical properties of sodium metal can be observed or measured. It is a soft, lustrous, silver- colored metal with a relatively low melting point and low density.

Extensive & Intensive Properties Physical properties may be intensive or extensive. Extensive properties depend on the quantity of the sample, length, volume, and mass. Intensive properties do not depend on the size of the sample and can be used to identify substances; density, boiling point, melting point, and malleability.

Chemical Properties The ability of a substance to combine with or change into one or more other substances. When Iron reacts with the Oxygen in the air we breathe, what happens? It starts to rust. When we place Iron in a Nitrogen gas filled chamber, nothing happens. There is no reaction.

States of Matter The physical forms of matter: Solid Liquid Gas

Solids Matter that has a definite shape and volume. Ex. Books, desks, clothes. Molecules are held close together and there is very little movement between them.

Liquid A form of matter that flows, has constant volume, and takes the shape of its container. Ex. Water Atoms and molecules have more space between them than a solid does, but less than a gas (ie. It is more “ fluid ”.)

Gases A form of matter that flows and conforms to the shape of it ’ s container and fills the entire volume of the container. Ex. Neon lights, air, oxygen Molecules are moving in random patterns with varying amounts of distance between the particles.

Changes of Matter  All matter, regardless of state, undergoes physical and chemical changes.  These changes can be microscopic or macroscopic.

Physical Changes A physical change occurs when the substance changes state but does not change its chemical composition. For example: water freezing into ice, cutting a piece of wood into smaller pieces, etc. The form or appearance has changed, but the properties of that substance are the same (i.e. it has the same melting point, boiling point, chemical composition, etc.)

Characteristics of Physical Changes Melting point Boiling point Vapor pressure Color State of matter Density Electrical conductivity Solubility Adsorption to a surface Hardness

Chemical Changes A chemical change occurs when a substance changes into something new. This occurs due to heating, chemical reaction, etc. You can tell a chemical change has occurred if the density, melting point or freezing point of the original substance changes. Many common signs of a chemical change can be seen (bubbles forming, mass changed, etc).

Chemical Changes

Reaction with acids Reaction with bases (alkalis) Reaction with oxygen (combustion) Ability to act as oxidizing agent Ability to act as reducing agent Reaction with other elements Decomposition into simpler substances Corrosion Characteristics of Chemical Changes

Exit Slip 1. What is Matter? 2. What are some examples of Physical Properties? 3. What are some things that occur during a Chemical Change? 4. What is the difference between Extensive and Intensive Properties?