Matter Unit 1. Warm Up 1/26/2015 Complete the following unit conversions: How many grams are in 10...

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Transcript of Matter Unit 1. Warm Up 1/26/2015 Complete the following unit conversions: How many grams are in 10...

MatterUnit 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 WednesdayFirst Test Friday

ACT Vocabulary

Arid – extremely dryHaughty – arrogant;

condescendingDeleterious - harmfulJubilation – joy; exultationAbbreviate – 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 cm3

Matter - Not Matter – Not Sure

Sort the following words into 3 categories:

Peanut butter Yourself Plastic food wrap Cotton fabric Time Carbon dioxide Light Water Air Energy Motion Fish An idea Garbage

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 changes2. gas produced3. temperature change4. 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 matterSodium Water Soil Coffee Oxygen Soup Salt WaterIron Ice Cream Nitrogen Eggs BloodTable Salt Milk Cola Air

Pure SubstancesElement

Composed of identical atomsEx. Copper wire, aluminum foil

Pure Substances

• Element– composed of identical atoms

– EX: copper wire, aluminum foil

Pure Substances

CompoundComposed 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 reactionCan 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

Example

compound

Example

Example

Mixtures

Homogeneous

Example

Example

Heterogeneous

Example

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 0.215 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 sources1. Chemical2. Nuclear 3. Kinetic4. Electrical5. 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.

Heat is __________________. Therefore, it is a _______________ change.

Phase change

Phase change

Solid

Endothermic – energy absorbed

Exothermic – energy released

Change of State (phase changes)

Phase change The 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 change1. 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 cm³?

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?

Rem

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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

https://www.youtube.com/watch?v=Sri3ItB8JvA

Matter properties (Issac)

https://www.youtube.com/watch?v=WGhGcrTVDVI

Matter properties parody

https://www.youtube.com/watch?v=EeWzyR1xap4