Chemistry Mid Term

electron

the negative subatomic particle in the electron cloud of an atom

electromagnetic radiation

form of energy that exhibits wavelike behavior as it travels through space

wavelength

unit of distance for measuring waves

frequency

number of waves that pass a given point in a certian time

emission spectrum

spectrum of light released from excited atoms of an element

heisenburg uncertainty principle

its impossible to determine the position and velocity of an electron or other particle simultaneously

octet rule

tendency of atoms to prefer to have 8 valance electrons

ions

atoms or molecules that have a change doe to having lost or gained electrons

lewis structures

a convenient and simple way to represent an element and its valance electrons

electrons are the negative subatomic particles in the atom but they behave more like…

waves

they can have different amounts of energy and thus different…

frequencies

electrons can absorb and release energy in the form of …

electromagnetic radiation

speed of light is …

constant

wavelength and frequency have an …

inverse relationship

left side of spectrum

longer wavelength, lower frequency, lower energy

right side of spectrum

shorter wave length, higher frequency, higher energy

order of electromagnetic spectrum

Radiowave, microwave, infrared, visible light (ROYGBIV), ultraviolet, x-ray, gamma ray

an electron in its ground state absorbs enough energy to …

jump energy levels

an electron in its excited state releases enough energy that it …

returns to its ground state

energy released in the form of …

electromagnetic radiation (visible light)

An atom is stable if it already has a …

full outer energy level of valance electrons (typically 8 e-)

the noble gases are already stable because …

they have full outer energy levels of valance electrons

Cations

atoms that lose e- in order to become stable which makes it positively charged and usually metals

anions

atoms that gain e- in order to become stable which makes it negatively charged and usually nonmetals

bohr model

lewis structure

observation

objective; based on senses

inference

subjective; based on perceptions

qualitive data

data based on qualities

quantitative data

data based on quantities (numbers and measurements)

conversion factors

ratios of equivalent values (meaning they equal 1)

Significant figures

the number of digits in a measurement that reflect how accurate the measurement is

dimensional analysis

a technique for converting numbers into different units, without changing their values

matter

anything that has mass and volume

mass

a measure of the amount of matter

volume

a measure of how much space something takes up

atom

the smallest unit of an element that maintains the identity of the element

element

a pure substance that can’t be broken down into anything simpler or more stable

compound

a pure substance that can be chemically broken down into simple and more stable substances; when atoms of two or more elements are chemically combined

substance

pure matter with a fixed composition throughout

mixture

combination of matter with a variable composition throughout

homogeneous mixture

a mixture with an even distribution of components

solution

when one substance (solute) is dissolved into another (solvent)

solubility

the measure of how well a solute dissolves in a solvent

aqueous solution

when the solute is dissolved in water

alloy

a solution of metals

heterogeneous mixture

a mixture with an uneven distribution of components

law of conservation of matter

matter is never created or destroyed, it only changes forms

proton

the positive subatomic particle in the nucleus of an atom

neutron

the neutral subatomic particle in the nucleus of an atom

electron

the negative subatomic particle in the electron cloud of an atom

valance electrons

electrons in the outermost energy level of the electron cloud

Quarks

Make up protons and neutrons and their attraction holds the nucleus together

atomic number

number of protons in an atom of the element; used to identify an element

mass number

number of protons and neutrons in the nucleus of an atom

groups

aka families; the vertical columns on the periodic table

Periods

the horizontal rows on the periodic table

isotopes

atoms of the same element with different numbers of neutrons

average atomic mass

weighted average of all of the different versions of an element; measure in amu

ion

a charged atom