Unit 2Matter and the ChangesThey Undergo

Phases of Matter The type and arrangement of the

particles in a sample of matter determine the properties of the matter

Three states of matter:

1. Solid2. Liquid3. Gas

Solids Definite shape, size, and volume

Molecules are closely packed together

Molecules are vibrating

Liquids No definite shape or size, but DOES have a

definite volume

Molecules are loosely packed together

Molecules are sliding and bouncing off of one another

Gases No definite shape, size, or volume

Molecules are separated by great distances

Molecules are traveling in a straight line of motion until they hit something

MatterMatter – Anything that takes up spacethat you can think of?

Matter has Physical and Chemical properties

Physical PropertiesPhysical Properties are

properties that describe the look or feel of a substanceExample: color, hardness, density,

texture, phase

Every substance has its own unique physical properties that can be used to identify the substance.

Physical PropertiesThese properties can change when

conditions change

However, are still unique (do not change into another substance)

Water to ice is a physical change (same chemical composition)

Chemical Reactions Propane Chemically Reacts

with oxygen to yield water and carbon dioxide

Propane and oxygen gas are the REACTANTS and water and carbon dioxide are the PRODUCTS

Chemical PropertiesChemical Properties – The ability of a substance to react with other substances or to transform from one substance to another

Chemical PropertiesAltering a Chemical Property:

Changes the way the atoms in the molecules are chemically bonded to one another. This is known as a Chemical Change.

Chemical Change means the materials are Reacting

What do we call this process of materials Reacting Chemically?

Chemical Reactions In a Chemical Reaction, new materials

are formed by a change in the way the atoms are bonded together

Atoms actually rearrange within the molecules UNLIKE A PHYSICAL CHANGE WHICH KEEPS

THE ORIGINAL CHEMICAL COMPOSITION

Evidence of a Chemical Change / Reaction Bubbles: Formation of a gas

Solid/Precipitate is formed

Release or absorption of energy (gets hot or cold)

A color changed in the system

Physical or Chemical Change?

SO…

What is a Physical Change ???

What is a Chemical Change ???

Check:Physical or Chemical Change?

Characterize the following scenarios as physical or chemical changes:

Water to iceCar: Iron to RustCrushing up a stone to a fine powderPhotosynthesisCutting grassPropane burns in a grill

Matter (Review) What is Matter?

Anything that has mass and volume (anything that takes up space)

Mass??

Volume??

Space an Object Occupies The Space an Object Occupies is the

object’s volume Volume can be measure by LxWxH if a

square or rectangle mL, L, cm3

But, how about an odd shaped solid??

Even better, how about a gas or liquid??

Quantity of Matter The Quantity of Matter is the Mass A marble is smaller than a ping pong

ball but has more mass It contains more MATTER

Mass can be measured using a balance g, kg

Mass is NOT Weight Mass is a measure of the amount of

matter an object contains

Weight, on the other hand, is defined as the force produced by gravity acting on a mass

Mass is the same on the moon, whereas weight will change

Units of Measurement Heavy, light, rough, smooth are

qualitative measurements

Mass and volume can be described in number values quantitative measurements

Volume is the Quantity measured in milliliters (the Units)

Système Internationale d’Unités(SI units) Scientists use the SI (Metric) system

for ALL measurements English (American) System is not

accepted The SI System is built on the seven bas

units listed below

Quantity Symbol Unit Abbreviation

Length l Meter m

Mass m Kilogram kg

Time t Second s

Temperature T Kelvin K

Amount of Substance

n Mole mol

Electric Current I Ampere A

Luminous Intensity Iv Candela cd

Elements Quiz #2#1-38 and 46-57 on Thursday