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What did Johann Dobereiner notice about the atomic mass of the middle element in a triad?
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What is the limitation of dobereiners periodic table?
All the elements known at that time could not be arranged as Dobereiner's triad's example: the three elements, nitrogen, phosphorus and arsenic have similar properties. Therefore they can be regarded to form a triad. However, the actual atomic mass if the middle element, phosphorus(P)(31.0u)is much lower than the average or mean(44.45u)of the atomic masses of nitrogen and arsenic. Thus, these three elements do not constitute a Dobereiner triad in spite of their similar chemical properties.
Was there any attempts to create the periodic table before Mendeleev attempt?
Yes. In 1817, J. W. Dobereiner pointed out that there were sets of three elements (Triads) which showed similar chemical properties. He also noticed the fact that the atomic weight of the central element of the Triad approximately is the mean of the atomic weights of the other two members. The properties of the middle element were in between those of the end members. He could identify only three triads from the elements known at that time. Hence this method of classification was discarded. Debereiner triads were: Li, Na, K Ca, Sr, Ba Cl, Br, I
What is an atomic radius?
Atomic radius is the measure from the middle of an atom to the outter edge. Usually mesured between two atom. Measure from the middle of one atom to the middle of another and then divide by two.
What middle school did Johann Gregor Mendel attend?
Saint Paul University Surigao
What is the term for the region of very high density in the center of the atom?
that is the nucleus. It is in the middle
What did Johann dobreiner do for the periodic table?
Dobereiner classified elements into groups of three. He introduced law of triads according to this law every element which comes in the middle of such a group has atomic mass equal to average of the atomic masses of first and third element. for example Lithium(Li) 7 Sodium(Na) 21 Potassium(K) 39
What are the merits of dobereiner's triads?
In 1817, a German chemist, Johann Wolfgang Dobereiner tried to arrange the elements with same properties into groups. He found out that some groups had only 3 elements and called them 'Triads'. He showed that when the 3 elements were written in their order of increasing atomic masses……the atomic mass of the middle element was roughly* the average of the masses of the other two elements.For example:Li Na K6.9 23.0 39.0Average of Li & K = 22.95, i.e., *roughly 23.0But since all the elements known then also couldn't be classified as this......'Dobereiner's Triads', as the table is known……wasn't useful……but the attempts of Dobereiner encouraged other chemists to correlate the properties of elements with their atomic masses.Sidz
Who created the triads and what was it?
Johann Dobereiner - noticed that the atomic weight of strontium fell midway between the weights of calcium and barium, elements possessing similar chemical properties. In 1829, after discovering the halogen triad (composed of chlorine, bromine, and iodine) and the alkali metal triad of (lithium, sodium and potassium) ***he proposed that nature contained triads of elements the middle element had properties that were an average of the other two members when ordered by the atomic weight (the Law of Triads)
What is the limitation of dobereiners periodic table?
All the elements known at that time could not be arranged as Dobereiner's triad's example: the three elements, nitrogen, phosphorus and arsenic have similar properties. Therefore they can be regarded to form a triad. However, the actual atomic mass if the middle element, phosphorus(P)(31.0u)is much lower than the average or mean(44.45u)of the atomic masses of nitrogen and arsenic. Thus, these three elements do not constitute a Dobereiner triad in spite of their similar chemical properties.
What is the contribution of Dobereiner to the periodic table?
He provided the base for the classification of elements he says the elements are atomic masses nearly same he arranged the atomic masses of the middle element is approximately the arithmetic mean of other two elements,He first gave us the ''Law of Triads''...where he made lists of three elements each, and showed that the mass of the middle element is approximately equal to the average mass of the other two elements.
What was Johann Pachelbel middle name?
Johann Pachelbel itself was his full name.
Was there any attempts to create the periodic table before Mendeleev attempt?
Yes. In 1817, J. W. Dobereiner pointed out that there were sets of three elements (Triads) which showed similar chemical properties. He also noticed the fact that the atomic weight of the central element of the Triad approximately is the mean of the atomic weights of the other two members. The properties of the middle element were in between those of the end members. He could identify only three triads from the elements known at that time. Hence this method of classification was discarded. Debereiner triads were: Li, Na, K Ca, Sr, Ba Cl, Br, I
What is Gregor Mendel's middle name?
Johann.
What is Johann pachelbels middle name?
He didn't have one.
What is the law of traid?
A German chemist Dobernier observed relationship between atomic masses of several groups of three elements called traids.In these groups the central or middle element had atomic mass average to the other two elements.
What is the electron configuration for element kr?
The lowest atomic number ion is Se^2-. The highest atomic number ion is Sr^2+. The ones in the middle are NOT Br^- or Rb^+. However, I do not know what the correct answer for those two is.
How do you get the number of neutrons in a element?
To find the number of neutrons in an atom you would subtract the protons from the atomic mass. The number of protons is equal to the atomic number. When dealing with an element with no net charge, the atomic number = the number of protons and also the number of electrons. The atomic mass - the atomic number (number of protons and electrons) = the number of neutrons
