Chapter 1 Matter & Change 1.2 Matter & Its Properties

Matter Matter- anything that has mass and takes up space. Mass- measure of the amount of matter Volume- amount of 3-D space an object occupies COMPOUND ELEMENT ATOM made from atoms of 2 or more elements pure substance of only one kind. smallest unit of an element that maintains the element’s properties

Properties We use properties and characteristics to define and group substances. Properties can be…. or Intensive Extensive Does not depend on amount of matter present. Melting & Boiling Points Depends on amount of matter present. Volume Mass

Physical vs Chemical Characteristics that can be observed without Δing the identity of the substance. Relates to a substance’s ability to undergo Δs that transform it into different substances. & Boiling Point Rusting & Burning

Physical Change Physical Change- change that does not alter the identity of the substance. Example: State Change- changes between the 3 states of matter. *Only a change in distance & interactions btw particles, not chemically altered.

Phase Differences Solid- has definite volume & shape; particles packed in fixed positions. Liquid- has definite volume & indefinite shape; particles close together but free-flowing. Gas- has indefinite volume & shape; particles are at great distance from each other. Plasma-high temperature, ionized phase of matter as found on the sun.

Chemical Change Chemical Change/Reaction- when 1 or more substances are changed into DIFFERENT substances. Example: Carbon plus Oxygen yields (forms) Carbon Dioxide Carbon + Oxygen → Carbon Dioxide Reactants Products

Conservation of Matter & Energy Even though the substances have changed & formed new substances, the amount of matter stays the same. When physical and chemical changes occur, energy is involved. (heat/light) It can be absorbed or released but NEVER created. It just changes form. Conservation of Energy

Classification of Matter Matter can be divided into 2 general categories, mixtures & pure substances Mixtures More than 1 substance Each component retains its own properties Does NOT chemically combine. Can be separated using physical properties

Separation Techniques Decanting Paper Chromatography Vaporization Centrifuge Filtration

Separation: Distillation

Two Types of Mixtures Heterogeneous Homogeneous -not uniform throughout -unevenly distributed Homogeneous -uniform in composition -same proportions throughout -often solutions copper sulfate malachite, a copper mineral

Pure Substances Element or compound Same composition throughout (Homogeneous) Fixed composition Every sample has the exact same characteristic properties Every sample has the exact same composition See pg. 18- Lab Chemicals

Chapter 1 Matter & Change 1.3 Elements

Elemental Composition

The Periodic Table Vertical columns Groups or Families Horizontal rows Periods Each element in a Group has similar properties. Properties change in a pattern across the Periods

The Periodic Table Below the table, are two rows called the Lanthanide & Actinide series. They actually belong in the table after the second column, but that would make the table too long and awkward.

Metals Conduct electricity & heat Typically solids at room temperature EXCEPT Hg Malleable- can be hammered/ rolled into sheets Ductile- can be drawn into a wire Have tensile strength- ability to resist breaking when pulled Found in columns 1- 13*

Nonmetals Poor conductors, Brittle Br is a liquid at room temperature. C, P, Se, S & I are solids at room temperature. Rest are gases at room temperature. Fewer elements are nonmetals than metals Found in columns 13* - 17

Metalloids/ Semimetals Separate the metals & nonmetals Have characteristics of both Solids at room temp. Important contribution- as semiconductors; Silicon Found on the “stairs” between columns 13 – 17

Noble Gases Generally unreactive Gases at room temperature. Found in Group 18

Former Names of Elements L is Latin; G is Greek