Chapter 1 Flashcards
Definition of Chemistry
The study of the composition, structure, and properties of matter and of the energy consumed or given of when matter undergoes a change
Definition of matter
Anything that occupies space and has mass
Definition of Mass
Defines the quantity of matter in an object
Definition of Energy
The capacity to do work
Definition of Pure Substances
A substance that has the same physical and chemical properties throughout and cannot be separated into simpler substances by a physical process. Made up of elements and compounds
Definition of physical process
A transformation of a sample of matter, such as a change in physical state, that does not alter the chemical identity of any substance in the sample
Definition of element
A pure substance that cannot be separated into simpler substances by any chemical process
Definition of Compound
A pure substance composed of two or more elements bonded together in fixed proportions that can be broken down into individual elements by chemical means
Definition of Mixture
A combination of two or more pure substances that can be separated by physical processes
Definition of homogenous mixture
Components are distributed uniformly throughout the sample and have no visible boundaries or origins, also called a solution
Definition of heterogenous mixture
components are not distinguished uniformly and may have distinct regions of different composition
Definition of Atom
The smallest particle of an element that retains the chemical characteristics of that element
Definition of molecule
An assembly of two or more atoms that are held together in a characteristic pattern by chemical bonds
Definition of chemical reaction
the transformation of one or more substances into different substances
Law of Constant Composition/Law of definite proportion
All samples of a particular compound contain the same elements combined in the same proportions
Definition of Cation/Anion
Cation: Positively charged ions
Anions: Negatively charged ions
Which formula type is most informative?
Structural
Methods for separating mixtures
- Centrifugation: a process for separating particles by applying a centripetal force to allow sedimentation of a heterogeneous mixture
- Electrophoresis: A process for separating molecules based on charged and size
- Filtration: A process for separating particles from a liquid or gas by passing the mixture through a medium that retains the particles
- Distillation: A separation technique in which more volatile components of a mixture are vaporized and then condensed, separating them from less volatile components
Properties of matter+examples
- Intensive: A property that is independent of the amount of substance present
Example: color, melting point, temp - Extensive: Varies with the quantity of substance present
Example: volume, mass - Physical: A property that can be observed without changing it into another substance
Examples: Luster, hardness, color, state, melting/boiling points, density - Chemical: A property that can only be observed by reacting it to form another substance
Example: Flammability
States of matter
- Solid: definite shape and volume
- Definite volume, flows to shape of container
- Gases: no definite shape or volume, expands to fill container
What causes a change in state?
Addition or removal of heat
Melting/freezing
Melting: Solid to liquid
Freezing: liquid to solid
Vaporization/condensation
Vaporization: Liquid to gas
Condensation: Gas to liquid
Sublimation/deposition
Sublimation: solid to gas
Deposition: Gas to solid
Formulas for converting between celsius and fahrenheit
C=(5/9)(F-32)
F=9/5C+32
Scientific Law
a concise statement/formula that is based on verified experimental observations of natural phenomena
Differences and similarities between compounds and elements
Similarities
- Composed of atoms
- Definite physical/chemical properties
- Can be isolated into pure form
Differences
- Compounds are more commonly found in nature
- Compounds can be broken down into simpler substances
- Compounds have different physical/chemical properties
