Chem- 1st semester
Terms
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- Halogens
- the nonmetals of Group 7A
- Spectator ions
- ions that are not directly involved in a chemical reaction
- Band of stability
- a region where the nuclei are stable on a plot
- Radioisotopes
- unstable isotopes
- Phase
- any part of a system with uniform composition and properties
- Neutrons
- a neutrally charged subatomic particle that is located in a nucleus
- Law of conservation of mass
- states mass cannot be created nor destroyed in a reaction or change
- Nonmetals
- elements that are generally nonlustrous and are generally poor conductors of electricity
- Chemical equation
- an expression representing a chemical reaction
- Homogeneous matter/ mixture
- uniform in appearance and with uniform properties throught(pure; same). //// 2 or more substances with one phase
- Theoretical yield
- the maximum amount of product that can be formed from any given amount of reactants
- Limiting reagent
- limits or determines the amount of product that can be formed in a reaction
- Liquid
- state of matter that flows, has a fixed volume, and takes the shape of its container
- Actual yield
- the amount of product that actually forms when the reaction is carried out
- Nucleus
- the central core of an atom
- Gamma radiation
- high energy electromagnetic radiation
- Excess reagent
- the reactant that is not completely used up
- Metals
- part of Group A that have high electrical conductivity and a high luster when clean
- Molecule
- the smallest electrically neutral substance that still has the properties of the substance
- Protons
- a positively charged subatomic particle located in a nucleus
- Percent yield
- the ratio of the actual yield to the theoretical yield expressed as a percent.
- Formula unit
- the lowest whole number ratio of ions in a compound
- Atomic mass
- the weighted averages of the masses of the isotopes of an element
- Sublimation
- the change of a substance from a solid to vapor without passing through the liquid state
- Law of multiple proportions
- ratios of masses is in whole numbers if 1+ compound is formed
- Ionic compound
- compounds composed of cations and anions
- Periodic law
- there is a periodic repetition of properties, when elements are arranged by atomic number
- Cathode ray
- a stream of electrons produced at the negative electrode containing a gas at low pressure
- Boiling point
- the temperature at which the vapor pressure of the liquid is equal to external pressure
- Mixture
- a physical blend of two or more substances
- Molecular compound
- compounds composed of molecules
- Complete ionic equation
- an equation that shows dissolved ionic compounds as their free ions
- Radiation
- the penetrating rays and particles emitted by a radioactive source
- Physical change
- a change that alters a given material without changing its composition
- Molar volume
- the volume occupied by 1 mole of a gas at STP (22.4 L)
- Beta particles
- the fast moving particles with 0 protons that are negatively charged and have a -1 subscript
- Alpha particles
- the particles emitted from alpha radiation that contain 4 protons and 2 neutrons
- Noble gases
- Nonmetals of Group 0 that undergo few chemical reactions
- Activity series of metals
- lists metals in order of decreasing reactivity
- Anion
- atoms or groups of atoms that have negative charges
- Gas
- matter that has no definite shape or volume; it adopts the shape of its container
- Compound
- substances that can be separated into simpler substances by chemical means
- Substance
- a sample of matter having a uniform and definite composition
- Avogadro's number, 6.02 x 1023
- the # of representative particles contained in one mole of a substance
- Atomic mass unit (amu)
- 1/12 the mass of carbon-12
- Beta radiation
- the emission of fast moving electrons from a radioactive source
- Physical property
- a quality or condition of a substance that can be seen without changing composition
- Chemical property
- the ability of a substance to undergo a chemical reaction and to form new substances
- Mole (mol)
- the amount of a substance that contains 6.02 x 1023 representative particles of that substance
- Combustion reaction
- an element or a compound reacts with oxygen, often producing energy
- Inner transition metals
- atomic numbers 57-70 and 89-102
- Law of definite proportions
- states masses in a compound is always proportional
- Transition metals
- Most of Group B
- Isotopes
- atoms that have the same number of protons but different numbers of neutrons
- Molecular formula
- shows the kinds and numbers of atoms present in a molecule of a compound
- Net ionic equation
- the equation that indicates only those particles that actually take part in the reaction
- Evaporation
- molecules from the surface break away and enter the gas or vapor state
- Half Life
- the time required for one-half of the nuclei of a radioisotope to decay to products
- Coefficient
- a small whole number that appears in front of a formula in a balanced chemical equation
- Atmospheric pressure
- results from the collision of air molecules with an object
- Mass
- the amount of matter that an object contains
- Radioactivity
- the spontaneous emissions of radiation from the nucleus of an atom.
- Alkali metals
- Consists of Group 1A
- Crystal
- a substance in which the atoms, ions, or molecules are arranged in a pattern called a crystal lattice
- Unit cell
- the smallest group of particles within a crystal that retain the geometric shape of the crystal
- Allotrope
- two or more different molecular forms of the same element in the same physical state
- Barometers
- devices commonly used to measure atmospheric pressure
- Neutron absorption
- a process that decreases the number of slow moving neutrons
- Gas pressure
- the force exerted by a gas per unit surface area of an object
- Alkaline earth metals
- Consists of Group 2A
- Pascal (Pa)
- the SI unit of pressure
- Molar mass
- a general expression used to refer to the mass of a mole of any substance
- Combination reaction
- a reaction where two or more substances combine to form a single one
- Heterogeneous matter// mixture
- matter with 2 or more physically distinct phases present. /// 2 or more phases
- Reactants
- the starting substances in a chemical reaction
- Atom
- the smallest particle of an element that retains properties of that element
- amorphous solid
- particles lack a regular internal arrangement: glass, plastic, gel. no shape or form
- Amorphous solid
- solids that lack internal structure
- Fission
- the splitting of a nucleus into smaller fragments
- Chemical formula
- shows the kinds and numbers of atoms in the smallest unit of the substance
- Electron
- negatively charged subatomic particles
- Polyatomic ion
- tightly bound groups of atoms that behave as a unit and carry a charge
- Fusion
- occurs when nuclei combine to produce a nucleus of greater mass
- Vapor
- a substance in the gaseous state that is ordinarily a liquid or solid at room temperature
- Matter
- anything that takes up space and has mass
- Ion
- atoms or groups of atoms that have a positive or negative charge
- Positron
- a particle with the mass of an electron but a charge of positive 1
- Periodic table
- an arrangement of elements into rows and columns based on similarities in their properties
- Group
- a vertical column in the periodic table
- Solid
- matter that has a definite shape and volume
- Transuranium elements
- the elements in the periodic table with atomic numbers above 92
- Chemical reaction
- one or more substances are changed to new substances
- Glass
- transparent fusion products of inorganic substances that have cooled to a rigid state without crystallizing
- Phase diagram
- gives the condition of temperature and pressure at which a substance exists as a solid, liquid, and gas
- Skeleton equation
- a chemical equation that does not indicate the relative amounts involved in the reaction
- Triple point
- the only set of conditions where all three phases can exist in equilibrium with each other
- Chemical symbol
- a one or two letter representation of an element
- Vaporization
- the conversion of a liquid to a gas or vapor
- Element
- the simplest form of matter that can exist under normal laboratory conditions
- STP (standard temperature and pressure)
- the conditions when the volume of a gas is usually measured
- Vapor pressure
- force due to the gas above a liquid
- Alpha radiation
- consists of helium nuclei that have been emitted from a radioactive source
- Mass number
- the total number of protons and neutrons of an atom
- Metalloids
- elements with properties intermediate between metals and nonmetals
- Kinetic energy
- the energy an object has because of its motion
- Transmutation
- the conversion of an atom of one element to an atom of another element
- crystaline solid
- repeat in a regular pattern
- Empirical formula
- a formula with the lowest whole-number ratio of elements in a compound
- Single replacement reaction
- one element replaces a second element in a compound
- Percent composition
- the percent by mass of each element in a compound
- Double replacement reaction
- an exchange of positive ions between two reacting compounds
- Solutions
- a homogeneous mixture
- Radioactive decay
- the process by which a radioactive element emits particles or rays and is transformed into another element.
- Decomposition reaction
- a single compound is broken down into two or more products
- Atomic number
- the number of protons in the nucleus of an atom
- Standard atmosphere (atm)
- the pressure required supporting 760 mm of mercury in a mercury barometer at 25°C
- Neutron moderation
- a process to reduce the speed of neutrons so that the reactor fuel can capture them
- Melting point
- the temperature at which a solid turns into a liquid
- Vacuum
- an empty space with no particles and no pressure
- Normal boiling point
- the boiling point of a liquid at 101.3 kPa
- Products
- the substances formed in a chemical reaction
- Distillation
- a purification process in which a liquid is evaporated and then condensed again to a liquid
- Cation
- any atoms or group of atoms that has a positive charge
- Catalyst
- a substance that speeds up the rate of a reaction but is not used up in the reaction
- Kinetic theory
- states tiny particles are in constant motion
- Representative elements
- Group a elements, because they have a wide range of properties
- Periods
- horizontal rows of elements in the periodic table