Crying with chem

the measured abundances of elements, the observed expansion of space, and the discovery of the cosmic microwave background

moving away

moving towards

the set of frequencies of the electromagnetic waves emitted by atoms of the element

positively charged particles in the nucleus of an atom

1 amu

1 amu

no charge, in nucleus

0 amu

negatively charged particle outside the nucleus

a process that occurs when an unstable atomic nucleus changes into another more stable nucleus by emitting radiation

length of time required for half of the radioactive atoms in a sample to decay

Take half of the initial mass go across until the line meets the curve. Then go down to find the time that corresponds to the half life.

Atoms of the same element that have different numbers of neutrons

the weighted average of the atomic masses of the naturally occurring isotopes of an element

Divide percents of naturally occurring isotopes by 100, multiply percent by mass, add all together.

number of electrons in a given sublevel

two of the electron's four quantum numbers., tell us more information about the properties of electrons and their orbitals.

Aufbau Principle, Pauli-exclusion Principle, and Hund's Rule

An electron occupies the lowest-energy orbital that can receive it

An atomic orbital may describe at most two electrons, each with opposite spin direction

electrons occupy orbitals of the same energy in a way that makes the number of electrons with the same spin direction as large as possible

pure substances and mixtures

Homo and Heterogenious mixtures

of the same kind

(adj.) composed of different kinds, diverse

Compound and elements

substance combines with another to form a new substance

a change of matter from one form to another without a change in chemical properties

color change, formation of a precipitate, formation of a gas, odor change, temperature change

single displacement, double displacement, combustion, synthesis, and decomposition

A + BC --> AC + B

AB + CD --> AD + CB

the process of burning something

combining parts into a whole

AB->A+B

dispersion force.

ttractive forces between the positive end of one polar molecule and the negative end of another polar molecule.

a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other.

an attractive force that results from the electrostatic attraction between an ion and a neutral molecule that has a dipole

attractions between molecules caused by the electron motion on one molecule affecting the electron motion on the other through electrical forces; these are the weakest interactions between molecules

attractions between oppositely charged regions of polar molecules

weak attraction between a hydrogen atom and another atom

an intermolecular force between an ion and the oppositely charged end of a polar molecule

the laws that state the mathematical relationships between the volume, temperature, pressure, and quantity of a gas

Energy can be transferred and transformed, but it cannot be created or destroyed.

Every energy transfer or transformation increases the entropy of the universe.

The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree celcius

Mass-atomic number

Equal to the atomic number

Electrons are equal to number of protons

Atomic number

Atomic mass

protons+neutrons

Protons

uneven distribution of electron density

one whose charge distribution is spherically symmetric when averaged over time

compounds made up of ions that form charged particles when an atom (or group of atoms) gains or loses electrons

chemical bond that involves the sharing of electrons to form electron pairs between atoms