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Flashcards in Ch 3 Section 1 Deck (31):
1

Democritus called natures basic particle an

Atom based on Greek word meaning "indivisible"

2

Aristotle thought that all matter was

Continuous and his opinion was accepted for nearly 2000 years

3

Neither the view of Aristotle nor that of Democritus was supported by

Experimental evidence do each remained speculation until the 18th century

4

Virtually all c he jets in the late 1700s accepted the modern definition of an element as a

Substance that cannot be further broken down by ordinary chemical means

5

It was clear that elements combine to form

Compounds that have different physical and chemical properties than those of the elements that form them

6

Great controversy as to whether elements

Always combine in the same ratio when forming a compound

7

Chemical reaction

Transformation of a substance(s) into one or more new substance

8

Particle theory of matter was was supported as early as

400 BC by Greek thinkers such as Democritus

9

Study of matter was revolutionized by a new emphasis on the

Quantitative analysis of chemical reactions

10

Aided by improved balances investigators began to

Accurately measure the masses of elements and compounds

11

Measurement of masses of elements and compounds led to the discovery of

Several basic laws

12

Law of conservation of mass

Mass is neither created nor destroyed during ordinary chemical reactions or physical changes

13

Discovery followed by assertion that regardless of where or how a pure chemical compound is prepared it is

Composed of a fixed proportion of elements

14

Law of definite proportions

Fact that a chemical compound contains the same elements in exCtly the same proportions by mass regardless of size of sample or source of compound

15

Known that 2 elements sometimes combine to form

More than one compound

16

Law of multiple proportions state that if two or more different compounds are composed of the same 2 elements then the ratio of the

Masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers

17

Dalton in 1808 proposed an explanation for the

Law of conservation of mass
The law of definite proportions
The law of multiple proportions

18

Dalton stated that elements were composed of

Atoms and that only whole numbers of atoms can combine to form compounds

19

(Daltons theory) all matter composed of extremely

Small particles called atoms

20

(Daltons theory) atoms of a given element are

Identical in size mass and other properties

21

(Daltons theory) atoms of different elements differ in

Size mass and other properties

22

(Daltons theory) atoms cannot be

Subdivided created or destroyed

23

(Daltons theory) atoms of different elements combine in

Simple whole number ratios to form chemical compounds

24

(Daltons theory) in chemical reactions atoms are

Combined separated or rearranged

25

According to dalton a theory the law of conservation of mass is explained by the fact that chemical reactions merely involve the

Combination separation or rearrangement of atoms and that during these processes atoms are not subdivided created or destroyed

26

Law of definite proportions results from the fact that a given chemical compound is always composed of the

Same combination of atoms

27

In the case of carbon oxides for law of multiple proportions, 2 to 1 ratio of oxygen masses results because CO2 always contains

Twice as many oxygen atoms as does carbon monoxide

28

By relating atoms to measurable property of mass dalton turned Democritus idea into a

Scientific theory that could be tested by experiment

29

Today we know that atoms are

Divisible into even smaller particles

30

We also know that a given element can have

Atoms with different masses

31

Daltons ideas that remain unchanged:

All matter is composed of atoms
Atoms of any one element differ in properties from atoms of another element