Aleks Placement Test: Chemistry With 100% Correct Answers

Aleks Placement Test: Chemistry With 100% Correct Answers Matter - answer✔✔Anything that has mass and takes up space; made of atoms Atoms - answer✔✔Basic unit of matter which cannot be broken down and contain m ostly empty space; contains three parts: the electron, proton, and neutron Elements - answer✔✔A pure substance that contains only one type of atom Compound - answer✔✔Two or more elements that are chemically bonded; includes ionic and covalent Mixture - answer✔✔Two or more substances that are together but not bonded Pure Substance - answer✔✔Substance that contains only one kind of compound Bose -Einstein Condensate - answer✔✔The state of matter with the lowest energy; basically a very cold solid Solid - answe r✔✔A state of matter with strong bonds Liquid - answer✔✔A state of matter with weak bonds Gas - answer✔✔A state of matter with no bonds Plasma - answer✔✔The state of matter with the highest energy; it uses ionization instead of bonds Robert Boyle - answer✔✔First to define an element; any substance is a substance unless it can be broken down John Dalton - answer✔✔Used and combined previous ideas to discuss the atom; elements are made of atoms; all atoms of an element are identical; atoms of different element s are different; law of constant composition; atoms are invisible Law of Constant Composition - answer✔✔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. Th omson - answer✔✔Discovered electrons and protons and developed the plum pudding model of an atom Electrons - answer✔✔The negatively charged particle in an atom; circles around the nucleus in the electron cloud Proton - answer✔✔The positively charged particle in an atom; located in the nucleus; determine the element Neutron - answer✔✔The neutral particle in an atom; it has no charge and is located in the nucleus Plum Pudding Model - answer✔✔A model of the atom th at depicts a sphere of positive charge with electrons scattered throughout Ernest Rutherford - answer✔✔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 - answer✔✔Elements located on the left side of the periodic table that want to lose electrons Characteristics of Metals - answer✔✔- Malleable - Ductile - Conductive - Lustrous Malleable - answer✔✔The ability to be molded into shapes Ductile - answer✔✔The ability to be pulled into wire Conductive - answer✔✔The ability to allow heat or electricity to pass through an object Lustrous - answer✔✔The ability to be shiny Nonmetals - answer✔✔Elements located on the right side of the periodic tabl e that want to gain electrons Metalloids - answer✔✔Elements placed in a stair -step line between metals and nonmetals; they have characteristics of both Diatomic Molecules - answer✔✔Elements that occur in pairs in their natural state; hydrogen, nitrogen, ox ygen, fluorine, chlorine, bromine, iodine Electronegativity - answer✔✔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 - answer✔✔The radius of an atom; decreases as you move left to right and increases as you move top to bottom Ionization Energy - answer✔✔The energy needed to rip off an electron; increases as you move left to right and decreases as you move top to bottom Ion - answer✔✔An atom that has gained or lost electrons Anion - answer✔✔An atom that gains electrons and has a negative charge; nonmetals Cation - answer✔✔An atom that looses electrons and has a positive charge; metals Isotope - answer✔✔An atom that has changed its number of neutrons Atomic Number - answer✔✔A unique number to each element that tells the number of protons and the number of electrons if the atom is neutral Atomic Mass - answer✔✔A number that tells the number of protons and neutrons in an atom Neut ron Number - answer✔✔Atomic Mass - Atomic Number Radioactive - answer✔✔A nucleus that spontaneously decomposes, forming a different nucleus and producing one or more particles; alpha, beta, and gamma ray Alpha Particle - answer✔✔One type of radioactive par ticle; 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 - answer✔✔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 - answer✔✔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 - answer✔✔The time required for half of the original sample of nuclei to decay; each radioactive nucleus of the same e lement has the same half -life; the shorter the half -life, the more likely a nucleus will decay Percent Abundance - answer✔✔Elements exist naturally in different isotopes, to the atomic mass listed on the table is an average Percent Abundance Equation - answer✔✔Average Mass = (%) •(Mass of Isotope A) + (%) •(Mass of Isotope B) +... Crest - answer✔✔The highest point of a wave Trough - answer✔✔The lowest point of a wave Wavelength - answer✔✔The distance between the crests of a wave; symbol is lambda