Properties of Matter a.
Matter - Anything that has mass and volume
Substance – matter that has the same composition and properties throughout. c.
Property – a characteristic that describes the object / substance
Element – Pure substance made up of only one kind of atom
Ex) iron nail, copper penny, gold ring
Compound - Pure substance made up of two or more elements chemically bonded
Ex) water, hydrogen peroxide, sugar, salt
Mixture - Combinations of two or more substances that do not combine to make a new substance.
Ex) air, blood, fruit salad, salt water
Cannot be separated by simple means b.
Elements gain new properties when they form a compound
Chemical formula – a way of describing the number of atoms that make up one molecule of a compound
Molecule – smallest particle of a substance that still has the properties of that substance
Each substance retains its own physical and chemical properties b.
Does not need to contain the same amount of each substance
Separation techniques: mechanically, filtering, sieves, sifters, d.
evaporation, magnets, distillation, centrifuge
Two types of mixtures – heterogeneous and homogeneous
Heterogeneous mixtures – heterogeneous means “different e.
throughout.” Heterogeneous mixtures have larger parts that are different from each other. Ex) milk, taco, suspensions
Homogeneous mixtures – homogeneous means “the same throughout.” Homogeneous mixtures have uniform composition, appearance, and properties. Ex) brass, black coffee, solutions
Suspension – a mixture in which the components are dispersed but large enough to see and to settle out.
Solutions – a mixture that looks like a single substance and has the same properties throughout. Solutions can be made of different combinations of solids, liquids, and gasses.
solute is the substance that dissolves in a solution
solvent is the substance that dissolves the solute sugar water ~ sugar – solute water - solvent
Water is called the universal solvent.
Substances that dissolve in another substance are soluble in the substance
Substances that do not dissolve in another substance are called insoluble in that substance.
Solubility – measurement that describes how much solute dissolves in a given amount of solvent at a given temperature. a.
Several factors, including time, motion, temperature, and contact b.
area, affect the rate of dissolving.
A saturated solution contains all of the solute it can hold under a given c.
An unsaturated solution contains less than the total amount of solute the solution can hold. d.
A supersaturated solution contains more solute than is normal for that temperature.
States of Matter a.
Solid – matter that has a definite shape and a definite volume; such as b.
a rock. i.
The particles are compact, touching each other and have a ii.
Solids have less energy than liquids and gases
Liquid – matter that conforms to the shape of its container with a definite volume; for example, water. i.
There is a flowing motion among particles as they are sliding or c.
rolling past each other.
Liquids have more energy than solids but less than gases.
Gas – matter than conforms to the shape and volume of its container. i.
The particles are free flowing with random motion and are not touching ii.
Gases have more energy than solids and liquids
State or Phase Changes:
Melting is a change from solid to liquid, energy is absorbed
Freezing is a change from liquid to solid, energy is released
Boiling is vaporization which occurs below the liquid’s surface as it changes to a gas, energy is absorbed
Evaporation is vaporization which occurs at the surface of a liquid as it changes to a gas, energy is absorbed
Condensation is a change from gas to liquid, energy is released.
Sublimation is a change from a solid to gas, energy is absorbed
Deposition is a change from a gas to a solid, energy
Quantitative observation - characteristics which can be measured
Extensive properties - directly proportional to the system size or amount of material
Qualitative observation - characteristics which are observed with our 5 senses
Intensive properties - does not depend on the system size or amount of material
States of matter
Appearance – looks, color, shape
Odor – smells
Tastes – flavor
Physical property i.
characteristic that can be observed without changing the identity of a substance qualitative and quantitative observations, extensive and intensive properties
Texture – smooth or rough
Chemical property i.
characteristic that cannot be observed without altering the substance
Ability to burn or support burning
Tendency to rust or corrode
Reaction to other
substances such as acids and bases
Unexpectedly produce a gas or solid
Physical and chemical changes
Physical change – form or appearance of matter changes, but composition stays the same. i.
Change does not produce a new substance
Shape can change, but substance does not
Dissolving a solid into a liquid is a physical change
State changes due to the amount of kinetic energy absorbed or released by substances
Chemical change results in a change in the substance’s composition i.
Energy may be gained or ii.
released during a chemical reaction
Color can change as a chemical reaction occurs iii.
Substances may change odor as a result of a chemical change
Formation of a gas or the precipitation of a solid can indicate a chemical change.
Law of conservation of mass – matter can never be created or destroyed as the result of physical or chemical changes