2 The Nature of Matter Flashcards
matter
anything that takes up space (volume) and has mass
chemistry
the study of the properties of matter and how matter changes
substance
a single kind of matter that is “pure”; it always has a specific makeup or composition and a specific set of properties
properties of all substances
Every form of matter has two kinds of properties – physical and chemical
physical properties
a characteristic of a pure substance that can be observed without changing it into another substance.
Examples: Density, hardness, texture, and color
pure substances
examples: salt, sugar, baking soda
composite substances (not pure)
examples: flour, baking powder, milk, eggs, and fruit
chemical properties
a characteristic of a pure substance that describes its ability to change into different substances
Examples: forming new substances with new properties; the ability to react; and flammability
element
a pure substance that cannot be broken down into any other substances by chemical or physical means
atom
the basic particle from which all elements are made
chemical bond
When atoms combine, they form a chemical bond, which is a force of attraction between two atoms
molecule
a group of two or more atoms held together by chemical bonds
compound
a pure substance made of two or more elements chemically combined in a set ratio.
Example: salt
chemical formula
a code which shows the elements in the compound and the ratio of atoms. For example, NaCl is the formula for Na (sodium/salt) + Cl (chloride).
properties of compounds
When elements are chemically combined, they form compounds having properties that are different from those of the uncombined elements
com-
prefix meaning with.
Example: compound
hetero-
prefix meaning different.
Example: heterogeneity
homo-
prefix meaning same.
Example: homogenous
endo-
prefix meaning in, inside, within.
Example: endogenous, having an internal cause or origin.
exo-
prefix meaning outside.
Example: exogenous, developing from external factors.
mixture
a combination of elements or molecules which do not form chemical bonds.
heterogenous mixture
you can see individual parts. Think of ChexMix.
homogenous mixture
the parts blend together so you can’t see the different molecules. Think of a salt-water solution.
methods to separate mixtures
5 ways: magnetic attraction, filtration, distillation, decantation, and evaporation
