Description : The names of the scientists; Newlands; Mendeleev; and Meyer are associated with the development of?
Last Answer : periodic table of contents
Description : Which of the following scientists was awarded the Nobel Prize in 1911 for the discovery of the radioactive elements, radium and polonium? w) John Dalton x) Dmitri Mendeleev y) Emil Fischer z) Marie Curie
Last Answer : ANSWER: Z -- MARIE CURIE
Description : This scientist gave the law- ‘Properties of elements are a periodic function of their atomic number.’ This property of the fundamental importance of atomic number was discovered by- (1) Johann Wolfgang Döbereiner (2) John Newlands (3) Dmitri lvanovich Mendeléev (4) Henry Moseley
Last Answer : (4) Henry Moseley Explanation: In 1913, Henry Moseley showed that the atomic number of an element is a more fundamental property than its atomic mass as described below.
Description : Iron which resembles Cobalt and Nickel in properties has been placed far away from these elements. This was one of the limitations of : (1) Modern periodic table (2) Newland's law of octaves (3) Dobereiner's triads (4) Mendeleev's periodic table
Last Answer : (2) Newland's law of octaves Explanation: Among the major limitations of Newlands Law of Octaves, some similar elements have been separated from one another while some dissimilar elements have been placed in the same column.
Description : Mendeleev arranged the elements in his periodic table on the basis of
Last Answer : atomic mass.
Description : (a) Why do we classify elements? (b) What were the two criteria used by Mendeleev in creating his Periodic Table? ... Justify your answer. -Chemistry 9th
Last Answer : (a) It is done so as to study the properties of elements conveniently. (b) Increasing order of atomic mass and similarities in chemical properties (especially nature and formulae of oxide and hydride formed). ... at that time. (e) They will be kept at same slot as they have same chemical properties.
Description : How many elements did Mendeleev introduce the modern periodic table ?
Last Answer : Mendeleev introduced the modern periodic table with 67 elements.
Description : What did Moseley use to reorder the elements of Mendeleev periodic table?
Last Answer : Henry Moseley discovered a relation between X-ray spectra and the atomic number of chemical elements.
Description : How did Mendeleev arrange the known elements in this periodic table?
Last Answer : Feel Free to Answer
Description : Why are isotopes not considered in Mendeleev’s periodic table?Name the elements which are predicted by Mendeleev as eka –silicon and eka –aluminum
Last Answer : Ans.Because Mendeleev gave priority to similarities in properties. Germanium and gallium
Description : In 1866, John Newlands, an English scientist, arranged the then known elements in the order of increasing atomic masses. He found that every eighth element had properties similar to that of the first. He called it ... of Pentamates (2) Law of musical notes (3) Law of Octaves (4) None of the above
Last Answer : (3) Law of Octaves Explanation: Newlands compared his discovery to the octaves found in music and thus, he called it the ‘Law of Octaves’. It is also known as ‘Newlands’ Law of Octaves’.
Description : Who created periodic table? A. Faraday B. Lavoisier C. Arrhenius D. Mendeleev (Answer)
Last Answer : D. Mendeleev (Answer)
Description : How Mendeleev organized his periodic table?
Last Answer : By the increasing Atomic Mass.
Description : How was Mendeleev and periodic table different from those of other chemists of the time?
Description : How did Mendeleev arrange the known element in his periodic table?
Last Answer : He arranged the elements in the increasing order of their atomicmasses and repeating periodic properties.
Description : Who invented the modern Periodic table? (1) Faraday (2) Mendeleev (3) Newton (4) Bohr
Last Answer : (2) Mendeleev Explanation: Dmitri Mendeleev was a Russian chemist who developed the periodic classification of the elements in 1869 A.D.
Description : What are the important features of Mendeleev periodic table?
Last Answer : Ans: based on(i) increasing atomic mass (ii) similarities in properties of elements.(iii) 63 elements divided in 7 horizontal row called periods and 8 vertical groups
Description : In his periodic table, Mendeleev could not assign a correct position to
Last Answer : Hydrogen
Description : Newlands' table, the elements were placed with the halogens - (1) Mn and As (2) Fe and Se (3) Ce and La (4) Co and Ni
Last Answer : (4) Co and Ni Explanation: Newlands' Law of Octaves suffered from lot of limitations, In order to fit elements into his table, Newlands ad justed two elements in the same slot, but also put some unlike elements under the same note.
Description : 1The elements of the second period of the Periodic Table are given below: Li Be B C N O F (a) Give reason to explain why atomic radii decrease from Li to F. (b) Identify the most (i) metallic and (ii)non-metallic element. -Science
Last Answer : a) It is because nuclear charge increases due to increase in atomic number, therefore, force of attraction between nucleus and valence electrons increases, i.e. effective nuclear charge increases, hence ... element is ‘F’ because it can gain electrons easily due to smallest atomic size.
Description : Atomic mass is not useful to construct the periodic table. Give reasons with an example. OR Why is atomic number is more useful than atomic mass to classify the elements?
Last Answer : Isotopes of an element have same atomic number but different atomic mass. They have to be placed in four places. This creates confusion because other elements occupied these positions.
Description : Do we have (or will have soon) a periodic table of sub-atomic elements?
Last Answer : http://www.bing.com/images/search?q=subatomic+elements+chart&qpvt=sub+atomic+elements+chart&qpvt=sub+atomic+elements+chart&FORM=IGRE ?
Description : Are the elements on the periodic table organized by their atomic number?
Last Answer : Yes. The elements are arranged in increasing order of atomic number.
Description : In the periodic table of elements, on moving from left to right across a period, the atomic radius – (1) decreases (2) increases (3) remains unchanged (4) does not follow a definite pattern
Last Answer : (1) decreases Explanation: The atomic radius is the distance from the atomic nucleus to the outermost stable electron orbital in an atom that is at equilibrium. It tends to decrease across a period from ... usually increases while going down a group due to the addition of a new energy level (shell).
Description : Referring to the periodic table of elements, it is found that with increasing atomic number. The atomic size in the same (A) Period increases (B) Period decreases (C) Group increases (D) Both 'b' & 'c'
Last Answer : Option D
Description : Name this chemical element. The principal use of this element has been in solid-state electronic devices, notably transistors. Its position in the periodic table is in group "4A". The element's atomic number is 32 and its chemical symbol is Ge.
Last Answer : ANSWER: GERMANIUM
Description : In the periodic table of elements, on moving from left to right across a period, the atomic radius (1) decreases (2) increases (3) remains unchanged (4) does not follow a definite pattern
Last Answer : increases
Description : Name the person who developed a table of elements which revealed regularities in elemental properties in 1869? w) Theodore Richards x) Antoine Lavoisier y) Dmitri Mendeleev z) Svante Arrhenius
Last Answer : ANSWER: Y -- DMITRI MENDELEEV
Description : Modern periodic law had been given by (1) Moseley (2) Mendeleev (3) Lother-Mayer (4) Lavoisier
Last Answer : (1) Moseley Explanation: In 1913, H.G.J Moseley in England proved that the more fundamental properties of an element are its atomic number. Therefore he suggested that the basis of classification of elements should be atomic number.
Description : State Mendeleev Periodic Law.
Last Answer : Ans: The chemical and physical properties of the elements are periodic functions of their atomic masses.
Description : According to Newland’s classification of elements, the properties of sulphur are similar to those of oxygen because sulphur is the
Last Answer : eighth element starting from oxygen
Description : X and Y are the two elements having similar properties which obey Newland’s law of octaves. How many elements are there in-between X and Y?
Last Answer : There are 6 elements between X and Y
Description : Which of the following is true regarding Newland’s Law of Octaves? (1) It worked well with only lighter elements. (2) It was applicable only up to calcium. (3) Both are correct (4) Both are incorrect. (4)
Last Answer : (3) Both are correct Explanation: Both the statements are correct. Hence, option C is correct.
Description : Who proposed first atomic theory? (1) E. Rutherford (2) De Broglie (3) John Dalton (4) D. I. Mendeleev
Last Answer : (3) John Dalton Explanation: Democritus first suggested the existence of the atom but it took almost two millennia before the atom was placed on a solid foothold as a fundamental chemical object by John Dalton (1766-1844).
Description : These two chemical elements, named after two world-renowned scientists, were first formed in a thermonuclear explosion which occurred in the South Pacific in 1952. The atomic numbers of these elements are 99 and 100. Their chemical symbols are Es and Fm. Name these elements.
Last Answer : ANSWER: EINSTEINIUM AND FERMIUM
Description : The Russian chemist who said that the properties of elements are periodic function of their atomic mass is
Last Answer : Dmitri Mendeleev.
Description : Taking first period and 17 th group of the periodic table, write gradation of properties with respect to the following: a) atomic size b) Ionisation energy c) electro positivity and electro negativity.
Last Answer : The elements of 1 st period are hydrogen and helium. a) Atomic size of hydrogen is larger then that of helium because atomic size decreases across a period. b) Ionisation energy of helium ... higher as it increases down the group. Electro negativity of fluorine as it decreases down the group.
Description : Nitrogen (atomic number 7) and Phosphorous (atomic number 15) belong to group 15 of the periodic table. Which of these will be more electro negative? Why?
Last Answer : Nitrogen will be more electro negative as it decreases down the group.
Description : What was the basis for Mendeleev classi- fication of elements?
Last Answer : Atomic weight
Description : Could you use average number of neutrons instead of atomic number to build up a periodic table good as that of mendeleyev?
Last Answer : it won't be possible since some elements exixts as isotopes
Description : Proceeding across a period in the Periodic Table, what atomic size trend is observed?
Last Answer : ANSWER: ATOMIC SIZE DECREASES
Description : A gaseous organic compound that is best known for its use in preservative solutions has the chemical formula HCHO (read: H - C - H CHEM-92; Short Answer: Give me the name and atomic number ... element is a clear, odorless gas. This element is one of the essential ingredients in the burning process.
Last Answer : ANSWER: OXYGEN ATOMIC NUMBER = 8
Description : As one goes across a period in the periodic table, the ionization energy generally increases for one of the following reasons. Is it because of the increasing w) atomic radius x) melting point y) nuclear charge z) density
Last Answer : ANSWER: Y -- NUCLEAR CHARGE
Description : What did Dmitri mendeleev have to do to unlock the hidden pattern of the elements?
Last Answer : What is the answer ?
Description : What did mendeleev do with the elements that did not fit?
Description : What is group names of periodic table?
Last Answer : Group names of Periodic Table: alkali metals, alkaline earth metals, scandium-titanium-vanadium-chromium-manganese-iron-cobalt-nickel-zinc-boron-carbon groups, pnictogens, chalcogens, halogens, noble gases.
Description : What are the names of the 8 groups in the periodic table?
Last Answer : alkali metals, alkali earth metals, halogens, noble gases, transition metals and there are only 5 not 8