0
What else can I help you with?
How could modern periodic law remove various anomalies of mendeleevs periodic table?
1.) The atomic mass in Mendeleev's periodic table does not increase regularly. therefore, it was impossible to predict the number of elements between two elements.The Modern periodic table has been made according to the increasing atomic number (Modern Periodic Law states that 'The properties of an element are the periodic function of its atomic number). The atomic number gives us the number of protons in the nucleus of an atom. the atomic number increases by one as we go from one element to the next. thus, this makes it easy to ascertain how many undiscovered elements may be there between two known elements.2.) Mendeleev's periodic table was made according to increasing atomic masses. we know that of an element have same chemical properties and atomic number, but different atomic masses. So, the concept of isotopes can not be satisfied.The Modern periodic table is according to increasing atomic numbers. Therefore, the problem of isotopes is easily dealt with.
How is moseleys basis for arranging the elements different from mendelees?
Moseley's basis and Mendeleev's basis both involved experimental measurements. But Moseley's involved X-ray properties, and X-rays were not discovered when Mendeleev first stated the Periodic Law. Atomic weight and atomic number follow nearly the same sequence, but there are three cases of reversal of order: Argon element 18 atomic weight 40.0; potassium element 19 atomic weight 39.1. (Argon was not discovered until 1894; first periodic table 1869). Cobalt element 27 atomic weight 58.9; nickel element 28 atomic weight 58.7. (Very small difference; Mendeleev gave these two elements identical atomic weights) Tellurium element 52 atomic weight 127.6; iodine element 53 atomic weight 126.9 (Major problem for Mendeleev -- he insisted that the atomic weight of tellurium had to be 125, but careful re-measurements continued to show 127.5-128) Moseley's atomic number is definitely a better basis for the periodic law than Mendeleev's original suggestion of atomic weight.
What did mendeleev do with the elements that did not fit?
Atomic weights were not always known to the same precision that they are today. There were small errors of measurement associated with their determination, and larger errors -- a factor of 1.5 or 2 -- associated with an incorrect attribution of valence. Mendeleev first formulated the Periodic Law, and then arranged the elements in a table according to the known values of atomic weight. In doing this he first came across beryllium -- an element with chemical properties very similar to aluminium. This element had been assumed to have a valence of 3 (like aluminium) and an atomic weight of 13.5 g/mol. Mendeleev realised that this could not be the case, but that if he assigned it a valence of 2 and an atomic weight of 9 g/mol, it fitted into the same group as magnesium and calcium. In some ways this was not appropriate, because chemically beryllium had a much closer resemblance to aluminium than to magnesium. However some of the compounds of beryllium had crystal structures isomorphous with the corresponding magnesium compounds, and this convinced Mendeleev that he was right to make this change in the molecular weight (and valence) assignement. Today we know that he was quite correct in making this change. The modern basis of the periodic law expresses it in terms of atomic number rather than atomic weight. There are just three cases among the elements where the atomic number order does not follow the atomic weight. (1) element 18 is argon, atomic weight 40.0 g/mol; element 19 is potassium, atomic weight 39.1 g/mol. But fortunately for Mendeleev's peace of mind and the general recognition of the periodic law among chemists argon had not yet been discovered! (2) element 27 is cobalt, modern atomic weight 58.9 g/mol; element 28 is nickel, modern atomic weight 58.7 g/mol. These two elements are very similar, and their atomic weights were at that time within experimental error of each other, so Mendeleev assigned both of the elements the same atomic weight, and correctly placed cobalt before nickel in his 1871 table. (3) element 52 is tellurium, modern atomic weight 127.6 g/mol; element 53 is iodine, modern atomic weight 126.9 g/mol. This was a real problem for Mendeleev. Iodine was a very common material, but tellurium was rather rare and infrequently encountered. It was very clear that iodine was closely related in chemistry to bromine and chlorine, while tellurium obviously fitted in with sulfur and selenium. But the then accepted values of atomic weight had Te at 128 g/mol while I was at 127 g/mol. Mendeleev was deeply convinced that the atomic weight of Te should be less than that of I. Scraping the bottom of the barrel, he was able to come up with a determination by a Czech(?) mining engineer that put the atomic weight of Te at 125 g/mol. A heated debate ensued with several carefully carried out determinations suggesting values between 127.5 and 128.0 g/mol , and Mendeleev insisting that such a value could not be correct because "the Periodic Law is a Law of Nature".
What is the significance of families on the periodic table?
Elements in Families on the periodic table have similarities. Elements in the same family as iron are magnetic. The air force had a tremendous problem. Traditional lubricants were not working under the stresses their new machinery used. All of their lubricants were carbon based. They looked at the next element in the same family on the periodic table. It was silicon. They made a lubricant based on silicon. It worked fine. The first diodes and transistors were made with Germanium. It is an expensive metal to produce. It is on the periodic table right above silicon. This led to a number of experiments and attempts to produce a transistor using silicone. Finally after many tries, it worked. Inexpensive silicon transistors could replace expensive germanium ones. You wrote your question because silicon is below Germanium on the periodic table.
What is Group A called in periodic table?
In the older periodic table, each group was divided into A & B sub-groups. The only problem with that was that there were two different conventions about which elements were labelled "A" and which were labelled "B". Groups 1 & 2 were clearly 'A' (elements like sodium and calcium) and 11 & 12 were clearly 'B' (elements like copper and zinc). But groups 3 through 10 were labelled 'A' in one convention and 'B' in another, and the opposite labels were used for groups 13 through 18.With the second labelling convention, groups labelled 'A' were known as 'main group elements', and groups labelled 'B' were 'transition metals', and that is still the case.Thus in the newer IUPAC scheme, groups 1, 2, and 13 through 18 are called 'main group elements'.
What is the difference in the modern periodic table and Mendeleev's table?
The periodic table is now complete and can be displayed using the integral atomic numbers. In Mendeleev's time there were still unknown elements. In fact, one of the primary uses of his table was to predict the properties of elements that had not yet been isolated. (His 1869 table included speculative names for some expected elements.) -- In Mendeleev's periodic table, transition elements were placed in another group. --In Mendeleev's periodic table, noble gases were written on left side. In the modern periodic table, noble gases are written on right side.
What was the problem with the first periodic table?
The first periodic table by Dmitri Mendeleev did not account for the discovery of isotopes (elements with the same number of protons but different number of neutrons) and did not leave spaces for later-discovered elements. Additionally, it did not show the relationship between atomic number and chemical properties.
How long did it take Mendleev to organize the periodic table?
Dmitri Mendeleev developed the periodic table over a period of around 6-7 years from 1869 to 1875. He arranged the elements based on their atomic mass and chemical properties, leaving gaps for undiscovered elements which he predicted would exist.
How could modern periodic law remove various anomalies of mendeleevs periodic table?
1.) The atomic mass in Mendeleev's periodic table does not increase regularly. therefore, it was impossible to predict the number of elements between two elements.The Modern periodic table has been made according to the increasing atomic number (Modern Periodic Law states that 'The properties of an element are the periodic function of its atomic number). The atomic number gives us the number of protons in the nucleus of an atom. the atomic number increases by one as we go from one element to the next. thus, this makes it easy to ascertain how many undiscovered elements may be there between two known elements.2.) Mendeleev's periodic table was made according to increasing atomic masses. we know that of an element have same chemical properties and atomic number, but different atomic masses. So, the concept of isotopes can not be satisfied.The Modern periodic table is according to increasing atomic numbers. Therefore, the problem of isotopes is easily dealt with.
How do you periodic table?
Periodic Table is an arrangement of elements in the increasing order of their atomic number. Not a problem to solve.
How do you solve periodic table?
Periodic table is an arrangement of elements in the increasing order of their atomic number. Not a problem to solve.
How do you count and find elements on the periodic table?
Finding elements on the periodic table, if you mean just as your question reads. Well, look at it and those symbols you see in the boxes are the elements. Counting won't be problem.
How could the modern periodic table remove various anomalies of mendeleevs periodic table?
1.) The Atomic Mass in Mendeleev's Periodic Table does not increase regularly. therefore, it was impossible to predict the number of elements between two elements.The Modern periodic table has been made according to the increasing atomic number (Modern Periodic Law states that 'The properties of an element are the periodic function of its atomic number). The atomic number gives us the number of protons in the nucleus of an atom. the atomic number increases by one as we go from one element to the next. thus, this makes it easy to ascertain how many undiscovered elements may be there between two known elements.2.) Mendeleev's periodic table was made according to increasing atomic masses. we know that of an element have same chemical properties and atomic number, but different atomic masses. So, the concept of isotopes can not be satisfied.The Modern periodic table is according to increasing atomic numbers. Therefore, the problem of isotopes is easily dealt with.
Why did chemists in 1869 not agree with Mendeleev's periodic table?
Everything. LoL, it was made by a female.
What problem in periodic table of Lothar Meyer?
Lothar Meyer's periodic table did not account for all known elements and did not correctly predict the properties of undiscovered elements. Additionally, it did not account for the concept of atomic number, which led to inconsistencies in the ordering of elements. Meyer's table also lacked a clear underlying periodic trend.
How is moseleys basis for arranging the elements different from mendelees?
Moseley's basis and Mendeleev's basis both involved experimental measurements. But Moseley's involved X-ray properties, and X-rays were not discovered when Mendeleev first stated the Periodic Law. Atomic weight and atomic number follow nearly the same sequence, but there are three cases of reversal of order: Argon element 18 atomic weight 40.0; potassium element 19 atomic weight 39.1. (Argon was not discovered until 1894; first periodic table 1869). Cobalt element 27 atomic weight 58.9; nickel element 28 atomic weight 58.7. (Very small difference; Mendeleev gave these two elements identical atomic weights) Tellurium element 52 atomic weight 127.6; iodine element 53 atomic weight 126.9 (Major problem for Mendeleev -- he insisted that the atomic weight of tellurium had to be 125, but careful re-measurements continued to show 127.5-128) Moseley's atomic number is definitely a better basis for the periodic law than Mendeleev's original suggestion of atomic weight.
What was the problem with Dobereiner's periodic table?
Dobereiner's periodic table, proposed in the early 19th century, attempted to group elements into triads based on their similar chemical properties. However, this classification system was limited as it only included a few elements and did not account for all known elements at the time. Additionally, the triads were based on average atomic masses, which were not always accurate due to the existence of isotopes. This led to inconsistencies and inaccuracies in the arrangement of elements.
