answersLogoWhite

0

The simplest criterion for arranging the atoms on the periodic table is that each atom in a row or period, except the first or last atom on the row, has an atomic number one more than the atomic number of the atom to its immediate left and one less than the atom to its immediate right in the same period, if there is such an element. If an element is the rightmost one in its period, the element with an atomic number one greater than that goes into column 1 of the next higher period.

The most common wide form arrangement of columns includes 18 columns numbered from 1 through 18. The lightest element, hydrogen, is placed in the first period in column 1 and the next lightest element, helium, is placed in the first period column 18, leaving columns 2 through 17 unoccupied in the first period.

Period 2 begins with the next lightest atom, lithium, in column 1, and the next lightest element after that, beryllium, in column 2. In the second period, columns 3 through 12 are left unoccupied, so that the atom with one higher than atomic number than beryllium, boron, goes into column 13. The same columns 3 through 12 are also left unoccupied in the third period, but are occupied in the remaining periods.

The number of each period corresponds to the first principal quantum number of the electrons in the atom with the highest such number, and the reason for leaving unoccupied places in the first three periods is connected with the second principal quantum characteristic of the electrons in the atom, the one sometimes called "shape" and designated by a letter s, p, d, or f. In the first period, only s electrons are allowed, and either one or two only may be present. In all the remaining periods, p electrons are also allowed, up to a maximum number of 6 such electrons. In the third and higher numbered periods, up to 10 d electrons are allowed along with the s and p electrons, and in the fifth and higher numbered periods, up to 14 additional f electrons are also allowed. Thus, the "space" of ten columns left unoccupied in the second and third periods corresponds to the ten d electrons that are allowed in the fouth and higher periods, but are not allowed in periods 1 - 2 and are not actually occupied until period 4.

The possibility of f electrons beginning with the fifth period but not actually observed until the sixth period is accommodated by two independent rows usually located at the bottom of the periodically arranged table. The element lanthanum, with atomic number 58, occupies period 6 column 3 and is the heaviest element that does not contain any f electrons. The next fourteen elements, with atomic numbers 58 through 71, occupy the upper one of these independent rows and contain f electrons with a principal quantum number of 5. After element 71, no more f electrons with principal quantum number 5 are allowed, and element 72 is entered in column 4 of period 6, which continues to be occupied in the normal way through the element radon with atomic number 86. The second independent horizontal row begins after actinium, element 89, in column 3 period 7 and continues through lawrencium, element 103. Heavier elements discovered so far return to the regular row of period 7.

User Avatar

Wiki User

12y ago

What else can I help you with?

Related Questions

What is periodic table in chemistry?

The periodic table in chemistry is an arrangement that is in tabular form for all the chemical elements. The elements are organized based on their electron configuration, atomic numbers and so on.


What is the ''periodic table of elements''?

Scandium.


How did chemists organize the elements that were known?

Chemists organized the elements by properties, specifically by atomic mass, to create the periodic table. This organization allowed them to identify patterns and trends among elements based on their chemical behavior. The periodic table was further refined over time as new elements were discovered and their properties were better understood.


What is Dmitri Mendeleev's arrangement of elements called?

Dmitri Mendeleev's arrangement of elements is called the periodic table. He organized the elements based on their atomic mass and chemical properties, leading to the development of the modern periodic table used today.


What type of matter is found in the periodic table?

The periodic table contains all the known elements, which are the basic building blocks of matter. These elements are organized based on their atomic number, electron configuration, and chemical properties.


What is the important work of Dmitri Mendeleev?

Mendeleev was the inventor of the Periodic Table. He organized all the known elements into the periodic table based on atomic number. He was also able to predict the existence of elements that had not yet been discovered based on gaps in the table he created. Based on observations of other elements in the groups he was also able to predict the characteristics of these unknown elements as well. NICE! dude


When did Dmitri set up the periodic table?

Dmitri Mendeleev set up the periodic table in 1869. He organized the elements based on their properties and atomic weights.


Who is known as the father of the periodic table elements?

Dmitri Ivanovich Mendeleev (1834 - 1907) is considered the father of the periodic table.


Which property of an atom's structure was used to organize the periodic table?

The periodic table was organized based on the property of atomic number, which represents the number of protons in an atom's nucleus. This arrangement allowed elements with similar chemical properties and reactivity to be grouped together in columns called groups or families.


Why was Mendeleev's periodic table considered a good model?

Mendeleev's periodic table was considered a good model because it organized elements based on their atomic mass and properties, allowing for predictions of undiscovered elements and their properties.


What determined the order of elements across a row in Mendeleev's periodic table?

Mendeleev organized the elements in his periodic table based on increasing atomic mass. He noticed that certain properties repeated periodically when the elements were arranged in this way.


What is an arrangement of elements in which are separated into groups based on a set of repeating properties?

Sounds like the Periodic Table of the elements.