What is the ratio of 100 and 10 ? Express your answer in the simplest form.
Answers
Answer:
Modern periodic table : long form of the periodic table
The classification of elements resulting from an arrangement of the elements in an
increasing order of their atomic numbers is the modern periodic table. The properties of
elements can be predicted more accurately with the help of the modern periodic table
formed on the basis of atomic numbers. The modern periodic table is also called the long
form of the periodic table.
In the modern periodic table the elements are arranged in accordance with their atomic
number. (see table 2.7) As a result, most of the drawbacks of Mendeleev’s periodic table
appear to be removed. However, the ambiguity about the position of hydrogen is not
removed even in the modern periodic table.
We have seen in the previous
standard that the electronic configuration
of an atom, the way in which the electron
are distributed in the shells around the
nucleus, is determined by the total
number of electrons in it; and the total
number of electrons in an atom is same
as the atomic number. The relation
between the atomic number of an element
and its electronic configuration is clearly
seen in the modern periodic table.
Structure of the Modern Periodic Table
The modern periodic table contains
seven horizontal rows called the periods
1 to 7. Similarly, the eighteen vertical
columns in this table are the groups 1 to
18. The arrangement of the periods and
groups results into formation of boxes.
Atomic numbers are serially indicated in
the upper part of these boxes. Each box
corresponds to the place for one element.
Apart from these seven rows, two rows are shown separately at the bottom of the
periodic table. These are called lanthanide series and actinide series, respectively. There
are 118 boxes in the periodic table including the two series. It means that there are 118
places for elements in the modern periodic table. Very recently formation of a few elements
was established experimentally and thereby the modern periodic table is now completely
filled. All the 118 elements are now discovered.
The entire periodic table is divided into four blocks,viz, s-block, p-block, d-block and
f-block. The s-block contains the groups 1 and 2. The groups 13 to 18 constitute the p-block.
The groups 3 to 12 constitute the d-block, while the lanthanide and actinide series at the
bottom form the f-block. The d-block elements are called transition elements. A zig-zag
line can be drawn in the p-block of the periodic table. The three traditional types of
elements can be clearly shown in the modern periodic table with the help of this zig-zag
line. The metalloid elements lie along the border of this zig-zag line. All the metals lie on
the left side of the zig-zag line while all the nonmetals lie on the right side.