chemlec

• Physical state of matter

  1. solid
  2. liquid
  3. gas
  4. plasma
  5. BEC - Bose einstein condensate
• solid - definite shape and volume
• Law of impenetrability state that two object can't occupy the same space at the same time.
• liquid has a definite volume but doesn't have a definite shape
• gases indefinite shape and volume
• properties of matter- distinguishing characteristics of a substance that is use in each identification and description
• physical property characteristics of a substance that ca be observed w/o changing the basic identity of a substance
• chemical property characteristics of a substance that describes the way the substance undergoes/resists change to form a new substances
• physical change there is no new property that will produce only physical form.

  structurally the same before and after the change
• vaporization changes from liquid to gas
• melting/fusion a changes from solid to liquid
• condensation changes from gas to liquid
• freezing/ solidification changes from liquid to solid
• sublimation changes from solid to gas w/o passing through the liquid state
• deposition transform into a solid passing through the liquid phase
• chemical change the breaking and forming of chemical bonds during a chemical reaction
• Matter, the “stuff” of which the universe is composed, has two characteristics: it has mass and it occupies space.
• physical properties of a substance include odor, color, volume, state (gas, liquid, or solid), density, melting point, and boiling point.
• We can also describe a pure substance in terms of its chemical properties, which refer to its ability to form new substances.
• Elements cannot be broken down into other substances by chemical means. Examples of elements are iron, aluminum, oxygen, and hydrogen.
• All of the matter in the world around us contains elements.
• The atoms of certain elements have special affinities for each other. They bind together in special ways to form compounds, substances that have the same composition no matter where we find them.
• any pure sample of an element contains only atoms of that element, never any atoms of any other element.
• A compound always contains atoms of different elements.
• A compound, although it contains more than one type of atom, always has the same composition—that is, the same combination of atoms.
• A mixture can be defined as something that has variable composition.
• A pure substance, on the other hand, will always have the same composition.
• pure substances are either elements or compounds
• A homogeneous mixture is the same throughout. For example, when we dissolve some salt in water and stir well, all regions of the resulting mixture have the same properties. A homogeneous mixture is also called a solution.
• . A heterogeneous mixture contains regions that have different properties from those of other regions. For example, when we pour sand into water, the resulting mixture has one region containing water and another, very different region containing mostly sand
• Mixtures are physical combinations of two or more pure substances.
• In physical combination, substances do not change into other substances when they became part of a mixture. An example is when copper sulfate powder is added to water, a mixture (solution) of copper sulfate and water is formed. The components look different, but no new substance is formed
• Pure Substances- Only one substance is present- Definite and constant composition- Properties are always the same at a given condition- Types:> Elements> Compound
• fixed composition; cannot be further purified.?

  pure substances
• a combination of two or more pure substances ?

  mixtures
• Mixtures- are two or more substance that are not chemically combined.-
• do not have a fixed composition

  • do not have constant boiling points or melting points
  • Variable composition
  • Components retain their characteristic properties
  • May be separated into pure substances by physical methods
  • Mixtures of different compositions may have widely different properties.
  • Variable combination of 2 or more pure substances?

  mixtures
• have definite composition ?

  compound
• cannot be separated by physical method; chemical method are required?

  compound
• the components of mixtures retain their individual possessions?

  mixture