elements, compounds, & mixtures. objectives describe pure substances describe the...
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Elements, Compounds, & Mixtures
• Objectives• Describe pure substances• Describe the characteristics of elements,
and give examples• Explain how elements can be identified• Classify elements according to their
properties
Section 1: Elements
3.1 Elements• Element- A ________ _______ that cannot be
separated into simpler substances by chemical or physical means.
• Pure Substance- A substance in which there is only ____ type of particles
Properties of Elements• Each element has its own characteristic properties.
• These include boiling/melting point, _______, reactivity, _____________, etc.
• An element may share one or two ____________ with another element, but it will not share all its properties with another element. There will be ________ properties for each element.
Classifying Elements
• You can use properties to identify elements. • Think about how many types of dogs there are.
• How do you tell one breed from another?
• Categories of Elements• Metals• ______________• ______________
Classifying Elements• Metal- an element that is _____ and conducts _______ and
electricity well
• Properties• ___________ – ability to be hammered
into sheets• Ductile – ability to be drawn into
wires
Classifying Elements
• __________ – an element that conducts heat and electric poorly• Properties
• 1. ____________• 2. brittle – not malleable
• Metalloid- an element that has properties of metals and _______________• Properties
1.some are shiny2. some are dull3. somewhat malleable and ductile4. some are good conductors of heat and electricity
5. some are poor conductors of heat and electricity
Classifying Elements
Classifying Elements Appearance Conductivity Physically Example
_________
Shiny
________
malleable., ductile
Lead, Copper
Nonmetal
Dull
________
Brittle
Sulfur, oxygen
Metalloid
Some Shiny/ some dull
Some good/ some poor
Somewhat malleable and ductile
________, ________
• Section Review• Please answer the objectives on your summary sheet
1. Describe pure substances
2. Describe the characteristics of elements, and give examples
3. Explain how elements can be identified
4. Classify elements according to their properties
Section 1: Elements
• Objectives• Explain how elements make up compounds• Describe the properties of compounds• Explain how a compound can be broken down
into its elements• Give examples of common compounds
Section 2: Compounds
3.2 Compounds• Compound- a substance made up of atoms of _____ or
more different elements joined by __________ ______• Examples: H2O (water), NaCl (table salt)
• A particle of a compound is called a ___________ • Elements do not randomly combine. They join into a specific
_______ according to their masses.
• Properties Compounds versus Elements• A compound will have different
______________ than the elements that make it up
Section 2: Compounds
Compounds
Sodium• Soft• Silvery, white metal• Reacts violently with
Chlorine Gas Poisonous Greenish-yellow
But when chemically combined…
You get……..
NaCl = _______________
Breaking Down Compounds• Some compounds can be broken down into their elements or
simpler compounds by _____________ means. • Sometimes energy in the form of _______ is needed to do
this.
• Section Review• Please answer the objectives on your summary sheet
1. Explain how elements make up compounds
2. Describe the properties of compounds
3. Explain how a compound can be broken down into its elements
4. Give examples of common compounds
Section 2: Compounds
• Objectives• Describe three properties of mixtures• Describe methods of separating the parts of a mixture• Analyze a solution in terms of its solute and solvent• Describe factors that affect solubility for solids, liquids, and
gases• Explain how concentration affects a solution
• Describe the particles in a solution, suspension, and colloid
• Explain the difference between colloids, solutions, and suspensions
Section 3: Mixtures
3.3 Mixtures• Mixture- A combination of two or more substances that are
not ____________ combined.• An example would be a salad (or salsa as in the picture). The
cheese, sauce, and dough are still the same items after you make the pizza.
Properties of Mixtures• Sometimes you cannot see all the components like in salt
water This is called a ____________ mixture. It includes salt and water.• Since mixtures are not chemically combined, you can separate
the different substances by ___________ methods. • Components in a mixture do not need to be in a specific ratio.
Sometimes you can just pick ingredients out of a mixture (pizza)This is called a _______________ mixture
Separating Mixtures Other ways to separate mixtures include:
evaporation – separates a mixture based on boiling points Ex: salt in water
• ___________ - a process to separate materials based on their size. Ex: coffee filters and a screen to find artifacts at a historical site.__________ – separates a mixture based on density.
Ex: crude oil – gasoline & propane
centrifuge – separates based on particle size Ex: blood
Compounds vs. mixtures
_____________ ______________ Made of elements, compounds or
bothMade of elements
No change in original properties of components
Change in original properties of components
Separated by physical means ______________________________
Formed by using any ratio of components
Formed using a set ratio of components
Mixture vs. compound vs. element
Solutions, Suspensions, & Colloids
Solutions• __________ - A mixture that appears to be a single substance.
• Particles are small & cannot be ____________• Solutions have the same _______________ throughout.• Example: Salt Water
• ___________ - Substance that is dissolved. (Salt)• Solvent- The substance in which the solute is dissolved. (water)
Hide the LOOT in the VENT!
Solutions Continued• The term soluble means able to __________. Insoluble means
unable to dissolve.• Solutions can be solids, liquids, or gases.
• __________- Measure of the amount of solute dissolved in a solvent. • This is expressed as g/mL• To increase solubility:
• _________• stir• crush – smaller particles
• How does temperature affect solubility?• For liquid solvents
• A higher temperature makes a gas _______ soluble• A higher temperature makes a solid _______ soluble
• USUALLY
• A higher temperature makes a liquid more soluble
Section 3: Mixtures
• To get solids to dissolve faster…Section 3: Mixtures
___________________________- Causes particles to separate and spread out faster
_____________- Causes particles to move more quickly and separate
________________- Spreads out solute to mix with solvent more quickly
Colloids• _________ A type of mixture in which the particles are
dispersed throughout but are not heavy enough to settle out• Particle size is larger than that of a solution but small enough
they will still pass through a filter.• Examples of colloids: _________, fog
Colloids Colloids scatter _________. (fog) You can actually see the beam of
light in the colloid.
Suspensions• Suspensions- A mixture in which the particles of a material are
dispersed throughout a liquid or gas but are ______ enough that they settle out.• Particles are large enough to settle out.• Suspensions can be separated by passing through a _________.• Examples: Italian salad dressing, muddy water
Elements, Compounds, Mixtures
Elements _____________ Mixtures
How many parts make it up?
1 2 or more 2 or more elements or compounds
Pure: more than one substance?
pure pure _______________
Chemically or physically combined?
__________ ______________ _______________
Chemical change to make them?
N/A Yes no
Fixed ratio? N/A Yes no
How separated: chemically/physically?
N/A Chemically physically
• Section Review• Please answer the objectives on your summary sheet
1. Describe three properties of mixtures2. Describe methods of separating the parts of a mixture3. Analyze a solution in terms of its solute and solvent4. Describe factors that affect solubility for solids, liquids, and
gases5. Explain how concentration affects a solution6. Describe the particles in a solution, suspension, and colloid7. Explain the difference between colloids, solutions, and
suspensions
Section 3: Mixtures