Substance-Matter with a composition that is always the same-Two types of substances: elements and compounds

Element-Consists of just one type of atom-organized on the periodic table-Each element has a chemical symbol

Compounds-Two or more types of atoms bonded together-Properties are different from the properties

of the elements that make it up-Each compound has a chemical formula

Mixtures-Matter that can vary in composition-Substances are not bonded together

-Two types of mixtures: heterogeneous and homogeneous

Matter-Anything that has mass and takes up space-Most matter on Earth is made up of atoms

-Two classifications of matter: substances and mixtures

Heterogeneous Mixtures-Two or more substances unevenly mixed-Different substances are visible by an unaided eye or a microscope

Homogeneous Mixtures-Two or more substances evenly mixed-Different substances cannot be seen even

by a microscope

Su

Substances physically combine to form mixtures

SuMixtures can be separated into substances by physical methods.

Physical Properties

• Physical properties are characteristics of matter that you can observe or measure without changing the identity of the matter.

absorptionareabrittlenessboiling pointcolorconcentrationdensityductilityelectric chargeflexibilityfluidity

lengthlocationluminancelustermalleabilitymagnetic fieldmassmelting pointmomentmomentumpermeability

pressureradiancesolubilitystrengthtemperaturetensionthermal conductivityvelocityviscosityvolumewave impedance

Particles that make up a solid are very close together and vibrate back and forth. This is why solids cannot easily change shape.

The particles that make up a liquid have more energy—and thus more motion—than the particles in a solid. Each particle still touches the particles around it, but the particles slide past each other. This is why you can pour a liquid.

The particles that make up a gas move very quickly, spread out, and fill their container.

Size-Dependent Properties• Mass

the amount of matter in an object– Sometimes mass is confused with weight, but they

are not the same! Weight is the pull of gravity on that matter. Weight changes with location, but mass does not.

• Volumethe amount of space something takes up.

–Volume is measured in milliliters (mL)

MiniLabFollow directions on page 360

Purpose: Can the weight of an object change?Hypothesis:Materials: balance, metal washers, spring scale,

beaker of 300 mL waterObservation: Write a paragraph of what you did

and observedConclusion: Answer the questions 1-3 for HW

Size-Independent Properties

Melting PointThe temperature at which a

substance changes from a solid to a liquid is its melting point.

Boiling PointThe temperature at which a

substance changes from a liquid to a gas is its boiling point.

Density-Density is the mass per unit volume of a

substance-M/V=D-Every substance has its own individual density-Density NEVER changes

because it’s a ratio of mass per volume

Size-Independent Properties

• Conductivity-the ability of matter to conduct, or carry along, an electric current.

• Thermal conductivity-the ability of matter to conduct thermal energy (heat).

• Solubility-the ability of one substance to dissolve in another– Solvent-the substance present in the largest

amount– Solute-the substance that dissolves in the solvent

Separating Mixtures

• Substance that make up mixtures are NOT held together by chemical bond. So, the properties of the individual substances do NOT change and they can be separated by physical properties.

• Compounds can NOT separated into the elements it contains because they are chemically bonded. Therefore, you can not separate the hydrogen from oxygen in water to get the two separate elements.