Ch 5 Section 1 Flashcards Preview

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Flashcards in Ch 5 Section 1 Deck (44):
1

Final noble gas Radon, was discovered in 1900 by

Friedrich Ernst dorn

2

Mendeleevs procedure left several

Empty spaces in his periodic table

3

In 1871, the Russian chemist boldly predicted the

Existence and properties of the elements that would fill the spaces

4

The success of mendeleevs predictions persuaded most chemists to accept his

Periodic table and earned him credit as the discoverer of the periodic law

5

Cannizzaros method enabled chemists to agree on

Standard values of atomic mass and initiated a search for relationships between atomic mass and other properties of the elements

6

Stanislao Cannizzaro presented a convincing method for accurately

Measuring the relative masses of atoms

7

Periodic law means that when the elements are arranged in order of increasing atomic number elements with

Similar properties appear at regular intervals

8

By 1860 more than... Elements had been..

60 discovered

9

Chemists had to learn the

Properties of these elements as well as those of the many compounds they formed

10

There was no method for accurately determine an elements

Atomic mass or the number of atoms of an element in a particular chemical compound

11

Different chemists used different atomic masses for the same elements resulting in

Different compositions being proposed for the same compounds

12

Cannizzaros method enabled chemists to agree on

Standard values of atomic mass and initiated a search for relationships between atomic mass and other properties of the elements

13

Mendeleev hoped to organize the elements according to their

Properties

14

Mendeleev noticed that when the elements were arranged in order of increasing atomic mass certain similarities in theirs

Chemical properties appeared at regular intervals. Such a repeating pattern is referrrrd to as periodic

15

Mendeleev created a table in which elements with similar properties were

Grouped together-- a periodic table of the elements

16

Mendeleev placed iodine after tellurium although this contradicted the pattern of listing the elements in order of increasing atomic mass, if allowed Mendeleev to place tellurium in a group of elements with which it shares

Similar properties

17

Mendeleevs procedure left several

Empty spaces in his periodic table

18

Henry Moseley examined the

Spectra of 38 different metals

19

Moseley discovered a previously

Unrecognized pattern

20

Moseley found that the elements in the periodic table fit into patterns better when they were sat ranged in

Increasing order according to nuclear charge or the number of protons in the nucleus

21

Moseleys work led to both the modern definition of atomic number and the recognition that

Atomic number, not atomic mass, is the basis for the organization of the periodic table

22

Modeled discovery was consistent with mendeleevs ordering of the periodic table by

Properties rather than strictly by atomic mass

23

Today mendeleevs principle of chemical periodic is correctly stated in what is known as

The periodic law

24

Periodic law;: the physical and chemical properties of the elements are

Periodic functions of their atomic numbers

25

Periodic law means that when the elements are arranged in order of increasing atomic number elements with

Similar properties appear at regular intervals

26

The periodic table is an arrangement of the elements in order of their

Atomic numbers so that elements with similar properties fall in the same column or group

27

Perhaps the most significant addition to the periodic table came with the discovery of the

Noble gases

28

Strutt snd Ramsay discovered

Argon in 1894

29

Argon: a gas in the atmosphere that had previously

escaped notice because of its total all of chemical reactivity

30

In 1868, helium had been discovered as a component of the

Sun, based on the emission spectrum of sunlight

31

To fit helium and argon into the periodic table Ramsay proposed a

New group

32

Ramsay also discovered

Krypton and xenon

33

Final noble gas radon was discovered in 1900 by

Friedrich Ernst dorn

34

The lanthanides are the

14 events with atomic numbers from 58 to 71

35

Because lanthanides are so similar in chemical and physical properties the process of

Separation and identifying them was a tedious task

36

The actinides are rev

14 elements with atomic numbers from 90 to 103

37

Lanthanides and actinides belong to periods

6 and 7 respectively, between groups 3 and 4

38

Lanthanides and actinides are usually set off

Below main portion of periodic table to save space

39

Periodicity with respect to atomic number can be observed in

Any group of elements in the periodic table

40

The differences in atomic number between the group 1 metals follow the same pattern as the

Differences in atomic number between the noble gases

41

Starting with the first member of groups 13-17 a similar

Periodic pattern is repeated

42

The atomic number of each successive elements

8,18,18, and 32 higher than the atomic number of the element above it

43

The reason for periodic is explained by the arrangement of

The electrons around the nucleus

44

The atomic number of each successive element is

8, 18, 18, and 32 higher than the atomic number of the element above it