1-2 Matter and Its Properties

Chapter 1 Notes

1-2 Matter and Its Properties

Volume-amount of 3-dimensional space an object takes up

Mass-a measure of the amount of matter

Matter-anything that has mass and takes up space

General properties of all matter: volume and mass

Basic Building Blocks of Matter

Atom-smallest unit of matter that maintains the properties of that element

Element-pure substance made of only one kind of atom. May not be broken down further and maintain its same properties

Compound-a substance made from the atoms of two or more elements, which are chemically bonded. May be broken down into elements, but will not maintain the properties of the compound

Molecule-smallest unit of an element or compound that retains all the properties of that element or compound

Properties and Changes in Matter

Extensive properties-depend on the amount of matter present

Volume, mass, energy

Intensive properties- do not depend on the amount of matter present

Melting point, boiling point

Physical property-characteristic that can be observed or measured without changing the identity of the substance

Melting point, boiling point

Physical change-a change in a substance that does not involve a change in the identity of the substance

Change of state: solid liquidgasliquid

States of matter:

Solid matter-has definite shape and volume

Liquid matter-has definite volume, but no definite shape

Gaseous matter-has no definite volume and no definite shape

Plasma-high temperature (energy) physical state of matter in which atoms lose their electrons

Changes of state do not change a substance’s properties

Chemical Property-relates to a substance’s ability to undergo changes that transform it into different substances

Chemical Change/ Chemicalreaction-change in which one or more substances are converted into different substances

Reactants-substances that react in a chemical change

Products-substances that are formed by a chemical change

The properties of the products vary greatly from those of the reactants

Energy is always involved in physical and chemical changes.

Energy may be in various forms, such as heat or light.

Sometimes a change in energy causes physical changes.

Sometimes increased energy may cause a chemical change.

Energy is not always the determining factor, though.

Law of conservation of energy-Energy is released or absorbed in reactions, but is never lost; it just changes form from before the reaction to after it.

Classification of Matter

Mixture-blend of two or more kinds of matter, with each retaining its original properties

Homogeneous Mixtures-uniform in composition

Solution-a homogeneous mixture

Heterogeneous Mixtures-not uniform throughout

Some mixtures may be filtered to separate
Some mixtures will settle out (may “decant” liquid)
A centrifuge may separate some solid-liquid mixtures
Paper chromatography may separate dyes from a liquid

Pure Substance-has a fixed composition and differs from a mixture

Every sample of a pure substance has exactly the same characteristic properties

Every sample of a pure substance has exactly the same composition
Are either compounds or elements

Lab chemicals are treated as if they were pure.

All chemicals have some impurities

“Reagent” grade is always purer than “technical” grade. See p. 18

1-3 Elements

Introduction to the periodic Table

Group-vertical column

Numbered 1-18
Elements in a group have similar properties
Family is a group with a name

Period-horizontal row

The closer together in a row, the more similar the properties
Lanthanide and actinide series fit after elements #57 and 89
PP 726-783 covers some representative elements

Types of Elements

Metals:

Shiny (lustrous)
Most are solids at room temperature
Element that is a good conductor of heat and electricity
Malleable-hammered or rolled into sheets
Ductile-can be drawn into a thin wire
High tensile strength (resist breaking when pulled)
Soft to hard
Brittle to malleable and ductile

Most have silvery or grayish luster

Copper is a representative metal, malleable and ductile, has high melting and boiling points, when heated it reacts with O2 in the air

Nonmetals

Many are gases at room temperature
Br is a liquid
Solids are brittle
Poor conductors of heat and electricity
There are fewer nonmetals than metals
Phosphorus is a representative nonmetal, has a lower melting and boiling point than metals, it is reactive, a component of all living things

Metalloids:

Has some characteristics of metals and nonmetals
Less brittle than nonmetals
Less malleable than metals
May be lustrous
Tend to be semiconductors of electricity

Noble Gases:

Group 18
Very unreactive
Gases at room temperature
Used in lighting
He used in balloons