0
Want this question answered?
Be notified when an answer is posted
Add your answer:
Earn +20 pts
How did mendeleev decide how to arrange his cards of elements?
Mendeleev used the analogy of playing the card game of solitaire to help him organize the known elements into a periodic table. The suits of the cards were analogous to the groups of the elements and the numeric values of the cards were analogous to the values of atomic weights.
Where are the elements with low electronegativity located on the periodic table?
Atoms with the lowest electronegativity values located on the leftmost part of the periodic table. The atom with the lowest electronegativity belongs to Francium.
What group in the periodic table is highly reactive in water?
the elements of ist A group are highly reactive toward water (even withice) and form a strong alkaline solution, their reactivity is due to large atomic sizes and low I.P values.
Highest IP values in 3A group elements?
Boron has the highest ionisation potential among group IIIA elements.
Is one of the seven elements that make up the army values?
selfless-service
What monetary values does nitrogen have?
What monetary valuse does nitrogen have
How did mendeleev decide how to arrange his cards of elements?
Mendeleev used the analogy of playing the card game of solitaire to help him organize the known elements into a periodic table. The suits of the cards were analogous to the groups of the elements and the numeric values of the cards were analogous to the values of atomic weights.
Where is halides in the periodic table?
The halogens are under group 17 (column 17) on the periodic table. They are in the column right next to the noble gases. They have the highest electronegativity values and typically exist as either anions or diatomic gases. Examples of these elements are fluorine, chlorine, bromine, and iodine.
Where are the elements with low electronegativity located on the periodic table?
Atoms with the lowest electronegativity values located on the leftmost part of the periodic table. The atom with the lowest electronegativity belongs to Francium.
What are values of watches?
They tell time, if it monetary value from a few £ $ to hundreds of thousands of £ $
Facts about Linus Pauling?
chemist who assigned "Pauling values" to every element in the periodic table, setting fluorine (the most electronegative) to 4.0 and basing every other elements electronegativity of of that number.
What is a time series in maths?
Time series is a method of using past data to predict future values. It is based on the assumption that there is an undelying trend to the data. To predict future values, we use the concept of moving averages.
Economic variables whose values are measured in monetary units are called?
Nominal Variables
Is coloring a penny bad?
It is unlawful to color or write on money regardless of monetary values.
________ assists countries in managing budget deficits and currency values.?
The International Monetary Fund
The non-monetary considerations that affect consumers' decisions are often based on what?
Values and beliefs
What are 2 main divisions of the periodic table?
DEFINITION:The orderly arrangement of elements is called "PERIODIC CLASSIFICATION".INTRODUCTION: When a very large number of elements become known to scientists , it was felt that they must be arranged in a systematic order because a systematic classification provides a clear idea and information about the properties of elements and make it easier to predict the properties of different elements. This classification provides the inter-relationship of scientific facts.Early Attempts at Classification Of Element:In old days, element were arranged in the ascending order of their atomic masses.1.Law of Triads/ DOBEREINER'S TRIADS:In 1829, a German scientist Dobereiner made use of the relationship between atomic masses and properties of elements.Drawback:This rule is not for all the elements.2.NEWLAND'S law of octave:In 1866, a British scientist, Newlands, reported his "law of octave" by arranging elements according to increasing order of their atomic masses. He noticed that "Every eight element, starting form any point, approximately has similar properties".Newland's arrangement was applicable only to a few elements after that it was failed.3.LUTHER MEYER'S CLASSIFICATION:In 1864, a German Chemist Luther Meyer published on incomplete periodic table .He included about 56 elements arranged in a group from I to VIII. He plotted the values of different physical properties and obtained different curves .In these graphs, he observed that element with similar physical properties occupy similar positions in the curveFor example :Alkali metals occupy the peak of the curves.Halogen occur on the ascending portions of the curve.4.MENDELEEV'S PERIODIC TABLE:In 1869, a Russian chemist, Mendeleev, on the basis of physical and chemical properties discovered a relation known as "PERIODIC LAW".According to the law:"The properties of element are the periodic function of their atomic masses".Mendeleev arranged the known elements according to increasing order of their atomic masses because,according to him fundamental property of an element was atomic mass.He further divided and arranged these eight groups into subgroups.Mendeleev's periodic table was very precise and provided the basis of modern periodic classification.Original statement of Mendeleev's periodic law:1.The elements,if arranged according to their atomic weights show an evident periodicity of properties.2.Elements which are similar with regards to their chemical properties have atomic weights which are either nearly the same value or which increase regularly.3.The arrangement of the elements or of groups of elements in the order of their atomic weights,corresponds with their so called valencies.4.The elements which are most widely distributed in nature have small atomic weights and sharply defined properties.They are therefore typical elements.5.The magnitude of the atomic weight determines the character of an element.6.The discovery of many as yet unknown elements may be expected.7.The atomic weight of an element may sometimes be corrected by the aid of a knowledge of those of adjacent elements.8.Certain characteristic properties of the elements can be foretold from their atomic weights.MERITS OF MENDELEEV'S PERIODIC TABLEMendeleev's periodic table offered the following advantages in understanding the properties of elements.1. There was a regular gradation in physical and chemical properties of elements.2. The group number of an element indicates highest oxidation state that it can attain.3. There were many vacant spaces in Mendeleev's periodic table for the elements to be discovered.He named them Eka-Boron, Eka-Aluminium and Eka-silicone He also predicted the properties of these undiscovered elements including atomic masses.These elements were discovered as Sc ,Ga and Ge with same features as he predicted.4. Mendeleev's arrangement helped to correct atomic masses of a number of elements.DEMERITS IN MENDELEEV'S PERIODIC TABLE1. For placing the elements in proper groups,the order of the elements according to atomic mass was reversed in certain cases. He placed Iodine (127) after Tellurium (128) Potassium (39) and Ni (58)after Co (59).Which is against his periodic law but correct according to properties.2. Mendeleev's periodic table does not provide a clear idea about the structure of atom.3. Lanthanide and Actinide have been assigned places in the periodic table which is against the periodic law.4. Alkali metal and coinage metals (Cu,Ag and Au) which differ widely in properties are placed into the same group.5. There is no separate position for isotopes in his periodic table.6. The change in atomic mass of two successive elements is not constant. Hence it is not possible to predict the number of missing elements by knowing the atomic masses of two known elements. DIC TABLE1. For placing the elements in proper groups, the order of the elements according to atomic mass was reversed in certain cases. He placed Iodine (127) after Tellurium (128) Potassium (39) and Ni (58) after Co (59). Which is against his periodic law but correct according to properties.2. Mendeleev's periodic table does not provide a clear idea about the structure of atom.3. have been assigned places in the periodic table which is against the periodic law.4. Alkali metal and coinage metals (Cu, Ag and Au) which differ widely in properties are placed into the same group.5. There is no separate position for isotopes in his periodic table.6. The change in atomic mass of two successive elements is not constant. Hence it is not possible to predict the number of missing elements by knowing the atomic masses of two known elements.DEMERITS IN MENDELEEV'S PERIODIC TABLE1. For placing the elements in proper groups, the order of the elements according to atomic mass was reversed in certain cases. He placed Iodine (127) after Tellurium (128) Potassium (39) and Ni (58) after Co (59). Which is against his periodic law but correct according to properties.2. Mendeleev's periodic table does not provide a clear idea about the structure of atom.3.have been assigned places in the periodic table which is against the periodic law.4. Alkali metal and coinage metals (Cu,Ag and Au) which differ widely in properties are placed into the same group.5. There is no separate position for isotopes in his periodic table.6. The change in atomic mass of two successive elements is not constant. Hence it is not possible to predict the number of missing elements by knowing the atomic masses of two known elements.
