Gen Chem 1 Flashcards
the study of matter
Chemistry
Occupies space, has mass, consists of atoms and molecules
Matter
Matter that can be seen with the naked eye
Macroscopic
Individual atoms and molecules cannot be seen by naked eye
Atomic
It is the examining results to see if there are alternative ways to interpret data
Scientific Method
Observing the color, appearance, size. No numbers or measurements
Qualitative Observations
Observing a quantity or a measurable attribute.
Quantitative Observations
The simplest type of matter, pure substances that cannot be broken down further, 118 recorded
Elements
Smallest indivisible unit of an element
Atom
Substance formed when two or more elements are combined in a defined ratio
Chemical compound
Collection of atoms held together by chemical bonds
Molecule
Contain only one type of element or compound
Pure substances
Have well-defined physical and chemical properties
Pure substances
State of matter that has a definite shape
Solids
State of matter that flow and take on the shape of the container
Liquids
State of matter with no fixed shape or volume
Gases
The change in physical property of a substance
Physical Change
The temperature at which a solid is converted to a liquid
Melting point
The temperature at which a liquid is converted to a solid
Freezing point
The temperature at which a liquid is converted to gas
Boiling point
The change in the chemical composition of the material
Chemical change
A substance made up of two or more elements or compounds that have not reacted chemically
Mixture
Can be separated by physical means into two or more pure substances
Not a pure substance
A mixture with constant composition throughout the material
Homogenous
A mixture with no uniform composition
Heterogenous
the means of separation of boiling point
distillation
the means of separation of density
Decantation and centrifugation
means of separation of state of matter
Filtration
means of separation of intermolecular forces
Chromatography
means of separation of vapor pressure
Evaporation
Means of separation of magnetism
Magnets
Means of separation of solubility
Filtration
are used to report measurement
SI units
what does SI unites mean
Syteme International d’Unites
is used to represent very large or very small numbers
Scientific Notation
the other term for the coefficient
Mantissa
Si unit of length
Meter (m)
Si unit of mass
Kilogram (kg)
the relative measure of how hot or cold a substance is
Temperature
Si unit of volume
Liter (L)
The capacity to do work or transfer heat
Energy
SI unit of energy
joule (J)
The physical property that relates the mass of a substance to its volume
Density
How close the values in a set of measurements are to one another
Precision
How close a measurement or a set of measurements is to a real value
Accuracy
a method of separation that often uses the hand
Mechanical separation
a method of mixture separation that takes advantage of the physical property of magnetism
Magnetic separation
method of separation that takes advantage of the physical property of the state of matter
Filtration
this can be use to separate solid particles of different sizes
Filter
To pour off a liquid, leaving another liquid or solid behind.
Decanting
Takes advantage of differences in density
Decanting
The separation of a mixture of liquids based on their boiling point
Distillation
Vaporizing a liquid and leaving the dissolved solids behind. Used to separate salt solutions
Evaporation
More dense components sink to the bottom and the less dense floats
Density separation
Circular motion helps denser components to sink to the bottom faster
Centrifuge
Uses the property of molecular attraction to separate a mixture
Paper chromatography
Dissolved substances crystallize out of a solution once their solubility limit is reached as the solution cools
Fractional Crystallization
the basic building block of matter
Atoms
these are single neutral particles
Atoms
these are neutral particles made of two or more atoms
Molecules
are formed when atoms or molecules lose or gain electrons
Ions
a positively or negatively charged particle
Ions
when an atom gains an electrons it’s charge becomes ________
Negative
when an atom loses electrons, it becomes ________-
positive
center of atom, generally made of neutrons and protons
Atomic Nucleus
Contains most of an atom’s mass
Atomic Nucleus
area surrounding nucleus that contains most of the space in the atom
Electron cloud
Found within an atomic nucleus and a positively charged particle
Proton
Found within the atomic nucleus and an uncharged particle
Neutron
Located outside the atomic nucleus and is a negatively charged particle
Electron
He proposes the indivisible unit of an element is an atom
Dalton (1803)
He discovered electrons
Thomson (1904)
He demonstrated the existence of a positively charged nucleus
Rutherford
He proposed fixed circular orbits around the nucleus for electrons
Bohr (1913)
equivalent to the number of protons
Atomic Number (Z)
tells us how many protons and neutrons there are in an atom
Mass number (A)
atoms of the same element that have the same number of protons but a different number of neutrons
Isotopes
isotopes that continuously and spontaneously break down/decay
Unstable
Isotopes that do not naturally decay but can exist in natural materials in differing proportions
Stable
a representation in writing of a chemical element or compound of a substance
Chemical Formula
the simplest form of expressing the relative number and the kind of atoms in a compound
Empirical formula
gives the actual number of atoms of each element in a molecule of the compound
Molecular formula
uses lines to represent chemical bonds and shows how the atoms in a molecule are connected to each other
Structural formula
Three-dimensional representation of molecules that are used to represent compounds
Molecular models
A model where atoms are represented by balls and chemical bonds as sticks
Ball-and-Stick
A model where atoms fill the space between each other to more closely represent our best idea for how a molecule might appear if we could scale it to a visible size
Space-filling model
