Matter Unit 1

Warm Up 1/26/2015 Complete the following unit conversions:  How many grams are in 10 kilograms?  How many meters are in 45 centimeters?  How many deciliters are in 0.5 liters?

Reminders  Elements Quiz Wednesday  First Test Friday

ACT Vocabulary  Arid – extremely dry  Haughty – arrogant; condescending  Deleterious - harmful  Jubilation – joy; exultation  Abbreviate – to shorten, abridge

Defining Matter Matter What it is: What it is not : Examples: How to measure:

Matter = “Stuff” Matter is anything that has mass and occupies space.  a. Mass - measured in grams  b. Space (volume): measured in mL or cm 3

Matter - Not Matter – Not Sure Sort the following words into 3 categories:  Peanut butterYourself  Plastic food wrapCotton fabric  TimeCarbon dioxide  LightWater  Air Energy  Motion Fish  An ideaGarbage

Properties and Changes in Matter A. Physical Properties 1.A characteristic that can be observed or measured without changing the identity of the substance. What are some examples?

B. Chemical Properties and Change 1. The ability of a substance to undergo changes that transforms it into different substance This means: It will have a new chemical formula. When it changes, it will undergo a chemical change.

We look for these Indicators of chemical change:  1.color changes  2.gas produced  3.temperature change  4. new substance formed  5. odor released

Classifying Matter into Major Categories Pure Substances  Pure Substance is matter for which a chemical symbol or formula can be written. Mixtures  Mixtures of matter are not chemically bonded and can be in any proportion. Classify these examples matter Sodium Water Soil Coffee OxygenSoupSalt WaterIron Ice CreamNitrogenEggsBlood Table SaltMilkColaAir

Pure Substances  Element  Composed of identical atoms  Ex. Copper wire, aluminum foil

Pure Substances  Compound  Composed of 2 or more elements in a fixed ratio  Properties differ from those of individual elements  Ex. Table salt (NaCl)

Mixtures  Variable combination of 2 or more pure substances

Mixtures  Substances are mixed together but they do not react to form new substances.  No chemical reaction  Can be separated physically– such as filtering, dismantling, etc.  They can be mixed in different proportions

 Heterogeneous: can see the parts  Homogeneous: looks uniform  Also called solutions  Can easily be mistaken to be a compound Mixtures

Matter Pure Substance element Example compound Example Mixtures Homogeneous Example Heterogeneous Example

Homework!  Find 5 examples of each type of matter (HINT: there are 4 types!)

Unit Conversions  How many Liters are in 670 mL ?  How many cg are in 1.25 grams?  How many mL are in kL?

Energy Introduction

F. Energy is always involved in physical and chemical change Energy definition: ability to transfer heat or do work Examples of energy sources 1.Chemical 2.Nuclear 3.Kinetic 4.Electrical 5.Gravity (or positional )

Heat and temperature are different Key concept in chemistry Heat is a form of energy (measured in joules) Temperature is a measure of hotness or coldness (measured in ºC or K) Actually the average kinetic energy of the atoms When a scientist heats a substance, she is adding ___________. This results in the atoms in the substance moving ___________ and so the temperature increases.

What about Temperature? We all know that some things feel hot, and others cold, but is there more to temperature than that? When an object feels hot, the atoms inside it are moving fast in random directions, and when it feels cold, they are moving slowly. Our body interprets that random atomic motion into what we feel as hot and cold, and a thermometer interprets that atomic motion as a certain number of degrees. So when I'm heating something, I'm just making its atoms move faster? Exactly. If the object is a solid the atoms are vibrating back and forth, and if it is a gas like the air, the atoms are flying around much like little balls.

Energy, usually in the form of heat, is involved in changes of state (phase changes.) Heat is __________________. Therefore, it is a _______________ change. Phase change Solid

Change of State (phase changes) Phase changeThe change is called: Is it exothermic or endothermic? Everyday example Solid to liquid Liquid to gas Solid to gas Gas to liquid Liquid to solid Gas to solid

F. Energy is always involved in physical and chemical change 1. Exothermic: We use the words: 2. Endothermic We use the words:

The Law of Conservation of Energy Energy is neither _______________ nor ______________ in a chemical reaction.

Density  Physical property  can be measured without destroying the sample  Use: to identify substances & product design  Density = mass volume

Density = mass (g) SOLID volume (cm³) Density = mass (g) LIQUID volume (mL) Measurements needed to determine density

Density: Example Problems 1. What is the density of a solid with a mass of 200 grams and a volume of 40 cm ³? 2. What is the density of a liquid which is measured at 25 grams and 20 mL? 3. What is the density of a piece of metal which is 2 cm x 5 cm x 3 cm and weighs 350 grams?

Density Formula To change to formula (2) Cross multiple or (2) Slide the variables diagonally across the equal sign D = M V

Density Calculation Practice D = M V Problem 1: A block of metal has a mass of 250 grams. The volume of 31.8 cm³. What is its density? Identify the metal. Problem 2: Aluminum has a density of 2.70 g/ cm³. The Al rod has a volume of 50 cm³. What is its mass? Problem 3: Gold has a density of 19.31g/ cm³. A gold coin has a mass of 200 grams. What is the volume of the coin? Remember: no naked numbers!

Why do substances have different density? - Identify and then write an explanation

Why do substances have different densities?  Explanation:  Structure:  Atoms of the substance:  Energy

Feedback:  Rate your understanding of the following topics:  Rating system:  1= confused  2= Fair but topic is not clear in my mind  3= Understand the topics but need more practice  4= Good, some practice & review will help.  5= Excellent, I know the topic and can do the problems.  For ratings 1 & 2: tell us what will help you

Feedback: Label  Units in chemistry & prefixes  Factor Label method - Unit conversions  Properties of Matter  Energy involved in changes  Classifying matter – pure substances & mixtures  Density calculations

LINKS  Matter song   Matter properties (Issac)   Matter properties parody 