ALEKS PLACEMENT TEST: CHEMISTRY WITH COMPLETE SOLUTIONS 100% 2023/2024

ALEKS PLACEMENT TEST: CHEMISTRY WITH COMPLETE SOLUTIONS 100% 2023/2024 Matter Anything that has mass and takes up space; made of atoms Atoms Basic unit of matter which cannot be broken down and contain mostly empty space; contains three parts: the electron, proton, and neutron Elements A pure substance that contains only one type of atom Compound Two or more elements that are chemically bonded; includes ionic and covalent Mixture Two or more substances that are together but not bonded Pure Substance Substance that contains only one kind of compound Bose-Einstein Condensate The state of matter with the lowest energy; basically a very cold solid Solid A state of matter with strong bonds Liquid A state of matter with weak bonds Gas A state of matter with no bonds Plasma The state of matter with the highest energy; it uses ionization instead of bonds Robert Boyle First to define an element; any substance is a substance unless it can be broken down John Dalton Used and combined previous ideas to discuss the atom; elements are made of atoms; all atoms of an element are identical; atoms of different elements are different; law of constant composition; atoms are invisible Law of Constant Composition Atoms of one element can combine with other elements to form compounds; a given compound always has the same relative numbers and types of atoms J.J. Thomson Discovered electrons and protons and developed the plum pudding model of an atom Electrons The negatively charged particle in an atom; circles around the nucleus in the electron cloud Proton The positively charged particle in an atom; located in the nucleus; determine the element Neutron The neutral particle in an atom; it has no charge and is located in the nucleus Plum Pudding Model A model of the atom that depicts a sphere of positive charge with electrons scattered throughout Ernest Rutherford Conducted an experiment in which he shot alpha particles at gold foil; roved there was a small, dense nucleus with a positive charge and that protons are positive Metals Elements located on the left side of the periodic table that want to lose electrons Characteristics of Metals - Malleable - Ductile - Conductive - Lustrous Malleable The ability to be molded into shapes Ductile The ability to be pulled into wire Conductive The ability to allow heat or electricity to pass through an object Lustrous The ability to be shiny Nonmetals Elements located on the right side of the periodic table that want to gain electrons Metalloids Elements placed in a stair-step line between metals and nonmetals; they have characteristics of both Diatomic Molecules Elements that occur in pairs in their natural state; hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine Electronegativity The ability of a molecule to attract electrons to it; increases as you move left to right in the table and decreases as you move top to bottom; fluorine is the hardest Atomic Radius The radius of an atom; decreases as you move left to right and increases as you move top to bottom Ionization Energy The energy needed to rip off an electron; increases as you move left to right and decreases as you move top to bottom Ion An atom that has gained or lost electrons Anion An atom that gains electrons and has a negative charge; nonmetals Cation An atom that looses electrons and has a positive charge; metals Isotope An atom that has changed its number of neutrons Atomic Number A unique number to each element that tells the number of protons and the number of electrons if the atom is neutral Atomic Mass A number that tells the number of protons and neutrons in an atom Neutron Number Atomic Mass - Atomic Number Radioactive A nucleus that spontaneously decomposes, forming a different nucleus and producing one or more particles; alpha, beta, and gamma ray Alpha Particle One type of radioactive particle; it is a essentially a helium nucleus; when this type of particle is released, the mass of the atom is conserved and so is the atomic number Beta Particle One type of radioactive particle; it is essentially an electron; when this type of particle is released, the atomic mass is conserved and the atomic number gains one (a neutron is changed to a proton) Gamma Ray One type of radioactive particle; it is a high energy photon of light and is used to release excess energy; the atom is not changed at all Half-Life The time required for half of the original sample of nuclei to decay; each radioactive nucleus of the same element has the same half-life; the shorter the half-life, the more likely a nucleus will decay Percent Abundance Elements exist naturally in different isotopes, to the atomic mass listed on the table is an average Percent Abundance Equation Average Mass = (%)•(Mass of Isotope A) + (%)•(Mass of Isotope B) +... Crest The highest point of a wave Trough The lowest point of a wave Wavelength The distance between the crests of a wave; symbol is lambda Frequency The number of waves that pass through a point in a given time; symbol is nu Amplitude The height of a crest or trough; crest to the zero line; absolute value Speed How fast a wave travels in a given distance Node Point on a wave where the wave returns to the zero line; a crest or trough is trapped between the two points Electromagnetic Spectrum The range of wavelengths or frequencies over which electromagnetic radiation extend Visible Light White light is passed through a prism and creates all visible colors; each color has its own frequency and wavelength Atoms and Colors When an atom is excited by energy it gives off its own characteristic colors of light Photon A light particle Speed of Light Equation C = w•f C is the speed of light w is wavelength in meters f is frequency in hertz Speed of Light 3.00•10^8m/s Continuous Spectrum Broken bands of colored light Bright Line Spectrum a.k.a. emission spectrum; occurs due to the energy an electron gives off as it travels from high to low energy; fireworks Dark Line Spectrum a.k.a. absorption spectrum; occurs due to the energy that an electron gains as it travels from low to high energy Energy using Planck's Constant E = h•f E is energy h is Planck's constant f is frequency in hertz Planck's Constant 6.626•10^-34 Joules/hertz