Advertisements
Advertisements
Question
What was the basis of the earliest attempts made for classification and grouping of elements?
Advertisements
Solution
The basis of the earliest attempts for the classification of elements was the chemical and physical properties observed by the scientists. Some reactions with known elements and compounds were compared.
The atomic weights were used to order them. To group them into groups they tried to observe the periodicity of the properties as the atomic weight increases. Law of triads and then the law of octaves was proposed. Doberneiner, Chancourtois, and Newlands proposed these laws and prepared some tables.
APPEARS IN
RELATED QUESTIONS
State whether the following statement is true of false:
The elements in a group have consecutive atomic numbers.
The element which can from an acidic oxide should be the one whose atomic number is:
(a) 6
(b) 16
(c) 12
(d) 19
The element X forms a compound X2Y. Suggest an element that Y might be and give reasons for your choice.
An element X (atomic number 17) reacts with an element Y (atomic number 20) to form a compound.
(a) Write the position of these elements in the modern periodic table.
(b) Write the formula of the compound formed.
Justify your answer in each case.
Alkaline earth metals have valency 2. This means that their position in the modern periodic table is in ______.
State whether true or false. If false, correct the statement.
Metals can gain electrons.
Identify the bond between H and F in the HF molecules.
Which of the following is a transition element?
Relate the names of the following scientists with the statements given below.
Arranged elements into groups containing three elements each.
How are elements grouped into various families in the periodic table?
