Asked in Chemistry, Science
Why are some elements on the periodic table left blank?
some elements in the periodic table are left blank because the elements with those atomic numbers are yet to be discovered. ...
Who is Moseley?
Who was Henry Moseley? Henry Moseley (1887-1915): A British chemist, Henry Moseley studied under Rutherford and brilliantly developed the application of X-ray spectra to study atomic structure; Moseley's discoveries resulted in a more accurate positioning of elements in the Periodic Table by closer determination of atomic numbers. Tragically for the development of science, Moseley was killed in action at Gallipoli in 1915 and he was a scientist, he discovered the atomic number of and element. :) and discovered the use of x ray spectrums ...
How many elements are missing in the periodic table?
one. element 117 has not been discovered. The atomic numbers of the elements start at one and end at 118, the limit of electrons an atom can hold. ...
Asked in Metal and Alloys
Who discovered the element lithium atomic number?
Lithium was first prepared in its simple substance metallic form in 1817, though its salts were known before this date. Atomic numbers, however, were not discovered until the analysis of X-ray line spectra by the British scientist Moseley in 1913. Lithium was among the first set of elements to have its atomic number 3 assigned in 1913. In the periodic system it was assigned position 2 in the order of atomic weights until the discovery of helium in 1895 pushed it back...
How are the actinide series elements created?
Elements with atomic numbers 89-94: natural elements. Elements with atomic numbers 95-98: artificial elements but they are also discoverd in nature as ultratraces. Elements with atomic numbers 99-103: artificial elements. ...
Asked in Chemistry, Periodic Table
What was the periodic table first arranged by. How has this changed?
In 1869 Russian teacher and scientist Dmitri Mendeleev, presented a periodic table of the elements based on atomic weights. The current periodic table is arranged by the atomic numbers of the elements. ...
Asked in Inventions, Prime Numbers, Mathematicians, Numbers
Who is the inventor of prime numbers?
Mathematics, including prime numbers, is discovered, not invented. Systems and methods we use are invented, but concepts of relationships between objects governed by logic, such as the prime numbers are discovered and named. As such, a more appropriate question might be "Who discovered prime numbers?" Many have discovered prime numbers; the first is unknown to mankind. ...
What do atoms of different elements have numbers of?
Different elements have different numbers of protons. The number of protons identifies the element. ...
What is the difference between transuranic elements and transactinides elements?
Transuranic elements are: elements with atomic numbers greater than 92 (now up to 118). Transuranic elements contain the transactinides elements. Transactinides elements are: elements with atomic numbers greater than 103 (now up to 118). ...