Ch. 1-3 Chemistry-The Atomic Theory Of Matter

Front 1

How did Ancient Greek Philosophy explain "substances"?

Back 1

In ancient Greek philosophy, all substances were thought to contain, in proportions to explain their properties, the four elements air, earth, fire, and water

Front 2

What did Greek philosophers think would happen, if a quantity of substance, such as gold, were divided in half, then divided again and again, without limit?

Back 2

Many believed it would yield up its constituent earth, air, fire, and water.

Front 3

What did the philosopher Democritus (460-ca. 370 B.C,) suggest about the repeated subdivision of a substance?

Back 3

He postulated that repeated subdivision of a quantity of gold or other material would eventually lead to a smallest particle, an unchangeable and indestructible atom ( named from the Greek "a" ("not") + tomos ("cut" ), meaning "not divisible").

Front 4

Scientific Method

Back 4

A formal means of understanding phenomena in which reproducible experiments and observations are used to construct verifiable hypotheses and theories.

Front 5

What are laws in science?

Back 5

More or less general statements of fact summarizing reproducible objectives and experiments. For example, the law of gravity
( "objects fall to earth if unsupported").

Front 6

What is a hypothesis?

Back 6

1) A provisional (accepted or adopted tentatively; conditionally; probationary) statement that explains the known facts of a situation and suggests new experiments or observations. 2) A suggestion put forward to account for a series of observations. 3) A hypothesis is an attempt to model reality.

Front 7

What is a theory?

Back 7

1) A hypothesis or set of hypotheses that explains diverse experiments and observations and does not contradict any solid factual findings. 2) A collection of ideas and concepts used to account for a scientific law.

Front 8

When did scientific progress towards understanding the microscopic nature of matter begin?

Back 8

In the 18th century.

Front 9

How did scientific progress towards understanding the microscopic nature of matter begin?

Back 9

It arose out of an interest in the nature of heat and the way things burn, or undergo combustion.

Front 10

What is combustion?

Back 10

1) The development of heat and light in a chemical reaction; usually with oxygen, but other oxidizing agents also support combustion. 2) A reaction in which an element or compound burns in oxygen.

Front 11

What is an oxide?

Back 11

It was observed when metal is heated in air, it was transformed into a "calx [kalks]"( the ashy substance that remains after metals, minerals, etc., have been thoroughly roasted or burned), which we now call oxide.

Front 12

What is phlogiston?

Back 12

Was the explanation for the phenomena of "calx" (the residue from burning metal in open air) that was popular in the first part of the 18th century. This substance called phlogiston was believed to be driven out of the metal by the heat of fire.

Front 13

What chemists experiment derived the Law of Conservation of Mass?

Back 13

French chemist Antione Lavoisier carried out an important experiment in 1775.

Front 14

What is the Law oof Conservation of Mass?

Back 14

1) Mass is neither created nor destroyed in a chemical change. 2) In a chemical change, an equal quantity of matter exists before and after the change. 3) Matter ( and specifically atoms) is neither created nor destroyed in a chemical reaction.

Front 15

What is the difference between "weight" and "mass" ?

Back 15

The mass of a body is an invariant (a quantity or expression that is constant throughout a certain range of conditions.) quantity, but its weight is the force exerted upon it by gravitational attraction (usually the earth).

Front 16

What is the Law of Definite Proportions?

Back 16

1) In a given chemical compound, the proportions by mass of the elements that compose it are fixed, independent of the origin of the compound or its mode of preparation.

Front 17

What is another name used for the Law of Definite Proportions?

Back 17

The Law of Constant Composition.

Front 18

What discovery was a crucial step in the development of modern chemistry?

Back 18

The Law of Definite Proportions.

Front 19

What is a non-stoichiometric [stoi-kee-uh-me-trik] compound?

Back 19

A compound in which the proportions of the constituent ( or component) elements are continuously variable ( or changeable )over some range.

Front 20

Who proposed the 1st atomic theory in the early years of the 19th century?

Back 20

An English scientist John Dalton.

Front 21

What are the postulates of Dalton's atomic theory of matter?

Back 21

1. All matter consists of solid and indivisible atoms.
2. All the atoms of a given chemical element are identical in mass and in all other properties.
3. Different elements have different kinds of atoms: these atoms differ in mass from element to element.
4. Atoms are indestructible and retain their identity in all chemical reactions.
5. The formation of a compound from its elements occurs through the combination of atoms of unlike elements in small whole numbered ratios.

Front 22

What law is Dalton's 4th postulate related too?

Back 22

Law of Conservation of Mass

Front 23

How did Dalton convey his atomic theory of matter?

Back 23

In 1808 he published "A New System of Chemical Philosophy".

Front 24

What law is Dalton's 5th postulate related too?

Back 24

The fifth postulate which can be called "Dalton's rule for chemical synthesis," is an attempt to explain the Law of Definite Proportions.

Front 25

What is a Scanning Tunneling Microscope (STM)?

Back 25

A relatively recent device that measure the properties of atoms by close direct observation.