Chemistry Unit 2

A ________ is a device that rotates a sample at high speeds causing the components of a mixture to separate.

centrifuge

A characteristic of a substance that can only be observed during a chemical reaction in which a substance either combines chemically with another substance or the substance breaks down chemically into simpler substances is called a(n) __________ property.

chemical

A mixture consisting of particles larger than 1nm but smaller than 1000 nm suspended in a dispersal medium.

colloid

This is the second category of matter, which are pure substances made of two or more elements chemically combined in definite proportions.

compounds

The law of __________ is a scientific law that states that mass is neither created nor destroyed in a chemical reaction.

conservation of mass

A method of separating a mixture of two solids that are both soluble in the same solvent but have different rates of solubility is called fractional ________.

crystallization

The Law of __________ proportions states that a chemical compound will always contain the same elements in the same proportions by mass regardless of the size of the sample.

definite

A chemical reaction in which hydrogen and oxygen molecules are removed from the reactants to produce water is called __________.

dehydration

Simple _________ is the process of physically separating a single-phase mixture into components with different boiling points.

distillation

This is the first category of matter, which describes pure substances that cannot be broken down into simpler substances by chemical or physical means.

elements

The __________ is a pattern of bands of visible light produced by an excited atom when it returns to its ground state after being heated in a flame or charged with an electric arc.

emission spectrum

_________ is the process of separating a solid phase from a fluid phase in a mixture by passing the mixture through a porous barrier that traps the solid.

filtration

A mixture in which the individual components remain distinct in separate phases without a uniform consistency is ___________.

heterogeneous

A mixture in which the individual components form a single phase with uniform consistency is ___________.

homogeneous

The phenomenon in which electrons are emitted from certain substances due to the absorption of light of specific frequencies is called __________.

photoelectric effect

A quantum of light is called a ____________.

photon

A change in a substance that does not involve a change in its composition is a(n) __________ change.

physical

A characteristic of a substance that may be observed or measured without changing the composition of the substance is a(n) __________ property.

physical

A principal quantum number of 7 would indicate that the ____________ energy level of an electron and its average distance from the nucleus were the highest.

primary

The quantum number (n) that specifies the primary energy level and its average distance from the nucleus is the ____________.

principal quantum number

The minimum amount of energy that can be gained or lost by an atom is a(n) __________.

quantum

A homogeneous mixture in which the solute is dissolved in a solvent; particles are less than 1nm in diameter.

solution

The substance used to separate components in a chromatography is called the ________ phase.

stationary

Each of the s, p, d, and f ___________ can only contain a maximum number of electrons.

sublevels

A heterogeneous mixture in which particles are not uniformly distributed throughout the mixture and will settle out unless it is constantly agitated; particles are larger than 1000 nm in diameter.

suspension

The __________ principle is a principle of quantum mechanics that states that orbitals of equal energy are each occupied by a single electron before any orbital is occupied by a second electron.

Hund's rule

All matter is made up of tiny, indivisible, indestructible particles called atomos, which are infinite in number and always in motion.

Democritus

The ____________ principle is a principle of quantum mechanics that states that an electron always occupies the orbital with lowest energy available.

Aufbau

The ____________ principle is the principle of quantum physics that states that it is impossible to determine accurately both the position and the speed of an electron at the same time.

Heisenberg uncertainty

An atom consists of a dense, positively charged nucleus surrounded by empty space in which negatively charged electrons orbit.

Ernest Rutherford

An atom consists of a cloud of positively charged material in which negatively charged particles called corpuscles are embedded.

J.J. Thomson

All matter is composed of extremely tiny particles called atoms that can combine in whole-number ratios with atoms of other elements to form compounds.

John Dalton

A German physicist named _________ proved that light emission and absorption can only be accomplished in discrete quantities of energy.

Max Planck

The ____________ principle is a principle of quantum mechanics which states that no two electrons in the same atom can have the same exact set of quantum numbers.

Pauli exclusion

The scientist who discovered the principle that no two electrons in the same atom can have the same exact set of quantum numbers is ___________.

Wolfgang Pauli

The quantum matrix was developed by a German physicist named ____________.

Werner Heisenberg

An interaction of a liquid in contact with a solid that results in the distortion, elevation, or depression of the surface of the liquid.

capillarity

This is the third category of matter, which are combinations of two or more pure substances, each of which maintains its individual chemical properties and can be separated by physical means.

mixtures

The _______ is a solution composed of the components of a mixture dissolved in a solvent to be separated by chromatography.

mobile phase

The Law of __________ proportions states that when more than one compound is formed by different combinations of the same elements, the different masses of one element that combine with the same mass of a second element will form ratios of small whole numbers.

multiple

The ____________ theory states that light, as well as electrons have the properties of both waves and particles.

wave-duality