science chapter elements, compounds, and mixtures

carbon dioxide

carbon and oxygen

Compounds

- made of elements - change in original properties of components -separated by chemical means - formed using a set ratio of components

mixtures

-Made of elements, compounds or both -no change in original properties of components - separated by physical means - formed using any ratio of components

Distillation

A process that separates a mixture based on the boiling points of the mixture's components. Also distillation is used to separate crude oil into components such as gasoline

Examples

Dry air (oxygen in nitrogen) Soft Drinks (carbon dioxide in water) Anti-freeze (alcohol in water) Saltwater (salt in water) brass (zinc in copper)

mixture

a mixture is a combination of two or more substances that are not chemically combined.

metalloids

also called semi-metals they have properties of both metals and nonmetals. some metalloids are somewhat malleable and ductile. some metalloids conduct heat and electric current

-

during a chemical reaction, the reactant atoms of two or more elements interact and join to form molecules of one or more compounds

solvent

in a solution, the substance in which the solute dissolves

solute

in a solution, the substance that dissolves in the solvent

-

mixtures can be separated by physical means, such as distillation, filtration, and evaporaton

nonmetals

nonmetals are elements that are dull **not shiny** and that are poor conductors of heat and electric current. solids tend to be brittle and unmalleable. few familiar objects are made of only nonmetals

table salt

sodium and chlorine

baking soda

sodium, hydrogen, carbon, and oxygen

...

A compound is made of elements that are mixed in specific mass ratio. However the components of a mixture do not need to be mixed in a definite ratio. For example granite is a mixture made of three minerals: feldspar, mica, and quartz Feldspar is pink. Mica is black. quartz is colorless. The granite of the pink one has more feldspar than it does Mika or quartz. so this paperweight is pink. The granite of the black one has more mica than it does other minerals. the granite of the gray one has more quartz that it does other minerals. even though the proportions of the minerals change the combination of the minerals is always a make sure called granite.

...

A measure of the amount of solute dissolved in a given amount of solvent is concentration concentration can be expressed in grams of salute per millimeter of solvent (g/mL) Solutions can be described as being concentrated in dilute.

...

A solution is composed of particles of two or more substances that are distributed evenly among each other solutions have the same appearance and properties throughout the mixture. The process in which particles of substances separate and spread evenly throughout a mixture is known as dissolving and solutions the solute in the substance that is dissolved in the solvent is a substance in which the solute is dissolved so you must be so you'll bowl or able to dissolve in the solvent a substance that is in soluble or unable to dissolve forms a mixture that is not a solution saltwater is a solution salt is soluble and or can dissolve in water so saw is the solute and water is the solvent went to liquids are two gases form a solution the substance that is present in the largest amount is the solvent

...

All mixtures share certain properties. When two or more materials are put together they form a mixture if they do not react to form a compound

...

For most solids solubility increases as temperature increases. So the amount of solute that can dissolve increases as temperature increases. But some solids such as cerium sulfate, become less soluble as temperature increases

states

Gas in gas Gas in liquid Liquid in liquid Solid in liquid Solid in solid

...

If you add too much sugar to a glass of lemonade some of the sugar cannot dissolve some of it sinks to the bottom to find the maximum of Mount of sugar that can dissolve you must know the solubility of sugar. Solubility refers to the ability of a solute to dissolve in a solvent at a certain temperature

example:

If you don't like mushrooms on your pizza you can just pick them off. this change is a physical change of the mixture. the identities of the substance do not change. but not all make shoes are easy to separate as pizza. you cannot just pick salt out of water. one way to separate the salt from the water is to heat the mixture until the water evaporates the saw is left behind

Evaporating

In the third step of the water is evaporated. the sodium chloride is left behind

...

No chemical change happens when a mixture is made so each substance in a mixture has the same chemical makeup it had it before the mixture formed. That is each substance and a mixture keeps its identity.

Dissolving

The first step water is added the mixture is stirred salt dissolves in the water sulfur does not

...

The particles and solutions are so small that they will not come out of solution. They also cannot be removed by filtering solute articles are so small that they do not scatter light.

Filtering

The second step the mixture is poured through a filter. the filter traps the solid sulfur

...

You may think that all solutions are liquids tap water soft drinks gasoline and many cleaners are liquid solutions. But solutions may also be gases air is a solution that is a gas solutions may even be solids steel is a solid solution. Alloys are solid solutions in which metals or nonmetals are dissolved in metals. Brass is an alloy of the metals zinc dissolved in copper. Steel is an alloy of the nonmetal carbon and other elements dissolved in iron

...

a chemical reaction is the process by which substances change into new substances. this process involves rearranging the atoms of a substance into new combinations with atoms of other substances. the atoms join in various patterns to form new substances that have different chemical properties. when two or more elements combine, a new compound is formed. the properties of the elements that formed the compound.

...

a compound has properties that differ from the properties of the elements that make up the compound. sodium reacts violently with water. chlorine is a poisonous gas. but when combined, these elements from a harmless compound that has unique properties. sodium chloride is safe to eat. it also dissolves (without exploding) in water.

compound

a compound is a pure substance composed of two or more elements that are chemically combined.

-

a compound is made up of two or more elements that are chemically combined to form a new substance with different properties

pure substance

a pure substance is a substance in which all of the "building blocks" particles are identical.

solution

a solution is a homogeneous mixture that appears to be a single substance. a homogeneous mixture throught which two or more substances are uniformaly dispersed

-

a solution is a mixture that appears to be a single substance but is composed of a solute dissolved in a solvent

-

an element is a pure substance in which there is only one kind of atom

element

an element is a pure substance that cannot be separated into simpler substance by physical or chemical means.

-

based on their properties, elements are classified as metals, nonmetals, or metalloids

...

compounds are all around you. they are in the food you eat, the clothes you wear, even the school supplies we use.

-

concentration is a measure of the amount of a solute dissolved in a given amount of solvent

-

each compound has a unique set of physical and chemical properties that differ from the properties of the elements that make up the compound

-

each element can be classified by a unique set of physical and chemical properties

...

each element can be classified by its unique set of properties. for example, each element has its own characteristic properties. these properties do not depend on the amount of the element present. characteristic properties include physical properties, and chemical properties. examples of physical properties are hardness, melting point, and density. examples of chemical properties are reactivity and flammablity

...

elements combine by reacting, or undergoing a chemical change, with on another. a chemical change, or reaction happens when one or more substances are changed into one or more new substances that have new and different properties

...

elements do not randomly join to form compounds. instead, elements join in a specific ratio according to their masses. for example, for water the ratio of the mass of hydrogen to the mass of oxygen is 1 to 8. this mass ratio can be written as 1:8. for water this ratio is always 1:8. that is, every sample of water has 1:8 mass ratio of hydrogen to oxygen. if a sample of a compound has a mass ratio of hydrogen to oxygen that is not 1:8, the compound cannot be water.

nonmetals

elements that are dull (not shiny) and that are poor conductors of heat and electric current. solids tend to be brittle and unmalleable. few familiar objects are made of only nonmetals.

metals

elements that are shiny and are good conductors of heat and electric current. they are malleable (they can be pounded or rolled into shape.) they are also ductile. (they can be drawn into thin wires.)

...

for elements, the building blocks particles are called atoms and are much too small for us to see. for example every atom in a 5 g piece of the element gold is like every other atom of gold. the particles of a pure substance are alike no matter when the substance is found.

water

hydrogen and oxygen

citric acid

hydrogen, carbon, and oxygen

...

like an element, each compound has its own physical properties. physical properties include melting point, density, and color. compounds can also be identified by their chemical properties. some compounds, such as calcium carbonate (found in chalk), react with acid. other compounds, such as hydrogen peroxide, react when exposed to light

metalloids

metalloids are also called semi-metals. they have properties of both metal and nonmetals. some metalloids are shiny, some are dull. metalloids are somewhat mealleable and ductile. some metalloids conduct heat and electric current

metal

metals are elements that are shiny and are good conductors of heat and electric current. they are malleable. ** they can be pounded or rolled into shape** , *** they can be drawn into within wires*** they are also ductile

...

nitrogen is one of the elements needed to make protein. another compound that plays an important role in life is carbon dioxide. you exhale carbon dioxide that was made in your body. plants take in carbon dioxide which is used in photosynthesis. plants and plant-eating animals get energy by breaking down these carbohydrates through chemical changes.

...

other physical properties, such as color, hardness, thermal conductivity, and texture could be added to the list. chemical properties might also be useful. for example some elements such as hydrogen and carbon are flammable. other elements, such as sodium, react with oxygen at room tempature.

...

some compounds can be broken down into their elements by chemical changes. other compounds break down to form simpler compounds instead of elements. these simpler compounds can then be broken down into elements through more chemical changes. for example, carbonic acid is a compound that helps give carbonated beverages their "fizz". when you open a can of soda, carbonic acid breaks downs into carbon dioxide and water and makes the soda fizz. this carbon dioxide and water could then be broken down into the elements carbon, oxygen, and hydrogen through chemical changes

solubility

the ability of one substance to dissolve in another at a given temperature and pressure

concentration

the amount of a particular substance in a given quantity of a mixture, solution, or ore

...

the compounds found in nature are not usually the raw materials needed by industry. often these compounds must be broken down to provide elements or other compounds that can be used as raw material. for example aluminum is used in cans and airplanes. but in nature, aluminum is found in the form of the compound aluminum oxide. pure aluminum is produced by breaking down aluminum oxid

...

the only way to break down a compound is through a chemical change. sometimes, energy is needed for a chemical change to happen. two ways to add energy to break down a compound are to apply heat and to apply an electric current. for example, heating the compound mercury (ll) oxide breaks it down into the elements mercury and oxygen.

...

two elements may have a property in common property can help you tell the elements apart. for example the elements helium and krypton are both unreactive gases. however the densities (mass per unit volume) of these elements differ from each other. helium is less dense than air. krypton is denser than air. if krypton-filled balloon is set free, it will sink to the ground.