Chemistry Quiz 1

Chemistry

The study of matter and the changes it undergoes, including how matter interacts with other matter and energy.

Science

A process for understanding and explaining natural phenomena through careful observation and experimentation.

Technology

The application of knowledge for practical purposes.

Green chemistry

Chemistry that uses materials and processes intended to prevent or reduce pollution at its source.

Sustainable chemistry

Chemistry designed to meet present needs without compromising the needs of future generations.

Applied research

Research directed toward solving a particular problem or developing a useful product or process.

Basic research

Research performed primarily to gain knowledge or answer fundamental questions without a specific immediate application.

Matter

Anything that has mass and occupies space.

Mass

A measure of the amount of matter in an object; it also measures an object's inertia.

Weight

The gravitational force acting on matter.

Element

A fundamental substance that cannot be broken down into simpler substances by chemical processes.

Compound

A substance made of two or more elements chemically combined in a fixed ratio.

Mixture

A physical blend of two or more substances whose composition can vary.

Variable

Something that can change during an experiment.

Scientific method

A process involving observation, hypothesis formation, experimentation, analysis, and development or revision of explanations.

Observation

Information obtained by observing or measuring some aspect of nature.

Hypothesis

A tentative, testable explanation of observations.

Experiment

A controlled observation designed to test a hypothesis.

Scientific law

A statement that summarizes consistent results of many observations and describes what happens.

Scientific theory

A detailed, testable explanation that describes why phenomena occur and organizes scientific knowledge.

Scientific model

A tangible object, diagram, or representation used to explain an otherwise difficult-to-observe process.

Physical property

A characteristic that can be observed or measured without forming a new substance.

Chemical property

A characteristic that can only be observed when a substance forms new substances.

Physical change

A change in appearance or physical form that does not change chemical composition.

Chemical change

A change in which the chemical composition changes and new substances form.

Solid

A state of matter with definite shape and volume; particles are closely packed and vibrate around fixed positions.

Liquid

A state of matter with definite volume but no definite shape; particles can move around one another.

Gas

A state of matter with neither definite shape nor definite volume; particles are far apart and move freely.

Density

The amount of mass per unit volume; d = m/V.

Density formula

d = m/V, where d is density, m is mass, and V is volume.

Density and floating

An object generally floats in water when its density is less than or equal to about 1.0 g/mL and sinks when greater.

Density column

A mixture of liquids arranged by density, with the least dense liquid at the top and the most dense at the bottom.

Metric system

A measurement system based on powers of ten and standard SI units.

Tera

The metric prefix meaning 10^12.

Giga

The metric prefix meaning 10^9.

Mega

The metric prefix meaning 10^6.

Kilo

The metric prefix meaning 10^3.

Centi

The metric prefix meaning 10^-2.

Milli

The metric prefix meaning 10^-3.

Micro

The metric prefix meaning 10^-6.

Nano

The metric prefix meaning 10^-9.

Pico

The metric prefix meaning 10^-12.

FLaReS

Falsifiability, Logical, Replicability, and Sufficiency—the four principles used to critically evaluate claims.

Falsifiability

A claim must allow evidence that could potentially show it to be false.

Replicability

Experimental evidence should be reproducible by subsequent experiments or trials.

Sufficiency

Evidence must be adequate to support the claim.

Risk

A hazard that can lead to loss or injury.

Benefit

Anything that promotes well-being or has a positive effect.

Desirability quotient

DQ = Benefits/Risks.

Mass versus weight

Mass stays constant with location; weight changes with gravitational force.

Physical versus chemical property

Physical properties are observed without forming new matter; chemical properties involve forming new substances.

Physical versus chemical change

Physical changes alter form but not composition; chemical changes alter composition.

Solid versus liquid

Both have definite volume, but solids have definite shape while liquids take the shape of their container.

Liquid versus gas

Liquids have definite volume; gases have neither definite volume nor definite shape.

Element versus compound

An element contains one type of atom; a compound contains two or more elements chemically combined in a fixed ratio.

Compound versus mixture

A compound has chemically bonded elements in a fixed ratio; a mixture contains substances physically combined in variable proportions.

Homogeneous mixture

A mixture with uniform composition throughout.

Heterogeneous mixture

A mixture whose composition varies from one part to another.

Law of conservation of mass

Matter is neither created nor destroyed in a chemical reaction.

Law of definite proportions

A particular compound always contains the same elements in the same definite proportions.

Law of multiple proportions

The same elements can combine in different whole-number ratios to form different compounds.

Isotope

Atoms of the same element with the same number of protons but different numbers of neutrons.

Dalton's Atomic Theory

Matter consists of atoms; atoms of each element are chemically similar; compounds form from atoms in fixed whole-number ratios; and chemical reactions rearrange atoms.

Modern modification of Dalton's theory

Atoms are divisible into subatomic particles, atoms of the same element can have different numbers of neutrons, and atoms can change in nuclear reactions.

Antoine Lavoisier

Scientist associated with demonstrating the conservation of mass during chemical reactions.

Joseph Proust

Scientist associated with the law of definite proportions.

John Dalton

Scientist associated with the law of multiple proportions and the atomic theory of matter.

Dmitri Mendeleev

The scientist commonly called the father of the periodic table.

Mendeleev's periodic table

The 1869 table arranged elements by increasing atomic mass, left gaps for undiscovered elements, and predicted properties of missing elements.

Periodic table

An organized arrangement of elements according to atomic number and repeating chemical properties.

Period

A horizontal row of the periodic table.

Group/family

A vertical column of the periodic table containing elements with similar properties.

Metal

An element generally found on the left side of the periodic table that conducts heat and electricity and tends to lose electrons.

Nonmetal

An element generally found on the upper-right side that tends to be a poor conductor and tends to gain electrons.

Metalloid

An element along the zigzag boundary with properties intermediate between metals and nonmetals.

Zintl border

The zigzag staircase-like boundary separating metals from nonmetals.

Alkali metals

Group 1 elements; highly reactive metals with one valence electron, excluding hydrogen as a typical nonmetal.

Alkaline earth metals

Group 2 elements with two valence electrons and generally reactive metallic properties.

Halogens

Group 17 elements with seven valence electrons and high reactivity.

Noble gases

Group 18 elements with very stable electron configurations and low reactivity.

Metal properties

Good conductivity, malleability, ductility, luster, and a tendency to lose electrons.

Nonmetal properties

Poor conductivity, varied physical states, and a tendency to gain electrons.

Metalloid properties

Mixed metallic and nonmetallic properties and intermediate electrical conductivity.

Periodic table location of metals

Mostly the left and center of the periodic table.

Periodic table location of nonmetals

Mostly the upper-right portion of the periodic table.

Periodic table location of metalloids

Along the zigzag staircase boundary.

Why elements in the same group are similar

They have similar outer-shell electron configurations and therefore similar chemical properties.

Chapter 3

Atom

The smallest characteristic particle of an element that retains the element's identity.

Photon

A discrete packet or quantum of electromagnetic energy.

Valence electron

An electron in the outermost occupied principal energy level that influences chemical behavior.

Ground state

The lowest-energy state of an atom.

Excited state

A state in which an electron has absorbed energy and moved to a higher energy level.

Proton

A positively charged subatomic particle in the nucleus with a mass of about 1 amu.

Neutron

An uncharged subatomic particle in the nucleus with a mass of about 1 amu.

Electron

A negatively charged subatomic particle outside the nucleus with a mass of about 1/1837 amu.

Atomic number

The number of protons in an atom's nucleus.

Mass number

The total number of protons plus neutrons in an atom's nucleus.