Chapter 2 What is Matter What is Matter

Chapter 2 What is Matter?

What is Matter? • Chemistry - is the study of matter and the changes that matter undergoes. • Matter- is anything that occupies space and has mass. • All living and non-living things are made of matter, chemistry affects all aspects of the natural world. • Element- a substance that cannot be broken down into simpler substances. – Example: Carbon, Oxygen, Nitrogen

What is Matter? • Atom- the smallest particle that has a property of an element. • Compound- a substance made of atoms of more than one element bound together. • Molecule- the smallest unit of a substance that exhibits all of the properties characteristic of that substance. – Example: H 20= water • Chemical Formula- the chemical symbols and numbers indicating the atoms contained in the basic unit of a substance. – Example: C 6 H 12 O 6 = Glucose • Pure Substance- any matter that has a fixed composition and definite properties.

What is Matter? • Mixture- a combination of more than one pure substance. • Heterogeneous mixture- substances are not uniformly mixed. – More than 1 layers are present. • Homogeneous mixture- substances are uniformly mixed. – 1 layer present • Miscible- describes two or more liquids that are able to dissolve into each other in various proportions • Immiscible- describes two or more liquids that do not mix into each other.

Matter and Energy • Kinetic Theory: – 1. All matter is made up of atoms and molecules that act like tiny particles. – 2. These tiny particles are always in motion. The higher the temperatures the faster the particles move. – 3. At the same temperature, more massive (heavier) particles move slower than less massive (lighter) particles.

States of Matter • There are three states of matter: solid, liquid , and gas • Solids-is a form of matter that has definite shape and volume. (incompressible) • Liquids-is a form of matter that has indefinite shape, flows, and yet has a fixed volume – nearly incompressible, expands slightly when heated • Gas- is a form matter that takes both the shape and volume of its container – easily compressed into smaller volume

Matter and Energy • Pressure: the force exerted per unit area of a surface. • Viscosity- the resistance of a fluid to flow. • Energy- the ability to change or move matter. • Evaporation- the change of a substance from a liquid to a gas. • Condensation- the change of a substance from a gas to a liquid. • Sublimination- the change of a substance from a solid to a gas • The law of conservation of mass- Mass cannot be created or destroyed. • The law of conservation of energy- Energy cannot be created or destroyed.

Properties of Matter • Chemical Property- the way a substance reacts with others to form new substances with different properties. • Reactivity- the ability of a substance to combine chemically with another substance. • Physical Property- a characteristic of a substance that can be observed or measured without changing the composition of the substance. • Melting Point- the temperature at which a solid becomes a liquid. • Boiling Point- the temperature at which a liquid becomes a gas below the surface.

Properties of Matter • Density- the mass per unit volume of a substance. – Density=Mass/Volume • Buoyancy- the force with which a more dense fluid pushes a less dense substance upward. • Chemical Change- a change that occurs when a substance changes by composition by forming one or more new substances. • Physical Change- a change in the physical form or properties of a substance that occurs without a change in composition.