Give reason: In the construction of periodic table, the periodic law is broken in

some places.

1 Answer

Answer :

Hydrogen resembles both the alkali metals and halogens. But it has been placed with the

alkalis.

The lanthanides and actinides have not been placed in the main body of the table.

Related questions

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 : Give reason: In the first period, hydrogen and helium are not placed adjacent to each other OR There is a big gap between hydrogen and helium in the periodic table.

Last Answer : Because Hydrogen and Helium belong to different groups. The Hydrogen element belongs to the 'Hydrogen' group, whereas the Helium element belongs to the 'noble gas'

Description : Position of Phosphorus in Periodic Table v , What is the reason ?

Last Answer : The position of phosphorus is in class V in the periodic table , because- i) the atomic number of phosphorus is divisible by 15 or 5 ii) the last layer of phosphorus atom has 5 electrons

Description : State Mendeleev’s periodic law. Write two achievements of Mendeleev’s periodic table -Science

Last Answer : Mendeleevs Periodic Law: Properties of elements are the periodic function of their atomic masses. Achievements:i It could classify all the elements discovered at that time. ii It helped in the discovery of new elements. iii it helped in the correction of the atomic mass of some of the elements.

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 : Explain the Modern Periodic Law , also define salient features of modern periodic table

Last Answer : Ans : Modern Periodic Law : Based on the concept of atomic number Bohr , Werner & Bury proposed the modern periodic law as ; The physical & chemical properties of all elements are ... periods. The physical & chemical properties of elements change from metallic to non metallic along a period.

Description : Explain the Mendeleev’s Law of classification of elements also describe advantages & disadvantages of his periodic table.

Last Answer : Ans : Mendeleeve's Law of Classification : Mendeleeve in 1869 arrange elements in order of increasing atomic masses. He placed chemically similar elements vertically beneath each other & concluded that : The ... metals. No Idea Of Atomic Structure : It failed to give the idea of atomic structure.

Description : Routine maintenance of dry-type transformers should include ______________. A. preventing the entrance of water from broken pipe lines steam lines B. keeping protective surfaces and insulating bushings free of ... debris C. periodic testing of insulation resistance with a megger D. all of the above

Last Answer : Answer: D

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 : 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 : What would happen if the protective tin coating over an iron bucket is broken in some places ?

Last Answer : Ans. Iron will corrode faster as the oxidation potential of Fe is higher than that of tin. 

Description : I have a single waving hand I'm present in places across the land On fairer days, I depart I shorten with a broken heart. What am I? -Riddles

Last Answer : A flag.

Description : The major constituent of laminate of safety glass, which holds the broken glass, pieces in their places during accident (and thus minimises the danger from flying glass fragments) is (A) Polyvinyl alcohol (B) Polyvinyl acetate (C) Polyvinyl butyral (D) PVC

Last Answer : (C) Polyvinyl butyral

Description : Give reason: Broken edges of glass have a slight greenish tinge.

Last Answer : Common sand used in the manufacture of glass contains some amount of iron salts. Iron salts give green colour to the glass.

Description : What is the periodic table of elements?

Last Answer : Answer: The periodic table of elements is a chart that arranges all known chemical elements in order of increasing atomic number, based on their electron configurations and chemical properties. ... as it allows scientists to predict the properties and behavior of different elements and compounds.

Description : Do chemists have to memorize all the elements of the periodic table?

Last Answer : answer:I don't see why they would have to , since most chemists don't work with all elements. On the other hand, just like readers memorized the alphabet and how to spell and ... have similar properties to each other, as well as isotopes of each. Familiarity sometimes breeds more familiarity.

Description : why is the periodic table symbol for sodium, Na ?

Last Answer : Many of them, like lead (Pb) are named after their latin roots.

Description : (a) What are groups' and periods' in the periodic table'? (b) Two elements M and N belong to group I and II respectively and are in the same period of the periodic ... Sizes of their atoms Their metallic characters Their valencies in forming oxides Molecular formulae of their chlorides -Science

Last Answer : (a) The vertical columns in the periodic table are called groups'. The horizontal rows in the periodic table are called periods'. (b) M' and N' belong to same period but group I ... oxides. Valency goes on increasing first and then decreases. MCI, NCI2 are molecular formulae of their chlorides.

Description : a) What is meant by periodicity in properties of elements with reference to the periodic table? (b) Why do all the elements of the same group have similar properties? (c) How will the tendency to gain electrons change as we go from left to right across a period? Why? -Science

Last Answer : (a) The repetition of same properties after definite interval is called periodicity in properties. (b) It is because they have same valence electrons therefore, have similar properties. (c) ... to right in a period because atomic size goes on decreasing and effective nuclear charge increases.

Description : The elements of the third period of the Periodic Table are given below: periodic-classification-of-elements-chapter-wise-important-questions-class-10-science-1 (a) Which atom is bigger, Na or Mg? Why? (6) Identify the most (i) metallic and (ii) non-metallic element in Period 3. -Science

Last Answer : (a) Sodium is bigger than magnesium as it has lesser nuclear charge so there is less force of attraction between nucleus and valence electrons and less effective nuclear charge. It is, therefore, ... the most non-metallic element because it can gain electrons easily due to its smallest atomic size.

Description : The names of the scientists, Newlands, Mendeleev and Meyer are associated with the development of (a) Atomic structure (b) Metallurgy (c) Periodic table of elements (d) Discovery of elements

Last Answer : Ans:(c)

Description : Which period have the largest number of elements in the periodic table?

Last Answer : The sixth period

Description : Where are the Largest atoms seen at the periodic table?

Last Answer : Bottom left

Description : Where are the smallest atoms seen at the modern periodic table?

Last Answer : Right hand top

Description : How many groups are there in the mod- ern periodic table?

Last Answer : Eighteen

Description : The vertical columns of the periodic table are called

Last Answer : Groups

Description : Modern periodic table was developed by?

Last Answer : Henry Moseley

Description : The horizontal rows of elements in the periodic table are called?

Last Answer : Periods

Description : 1st noble gas group in the periodic table?

Last Answer : Helium

Description : First element in the periodic table?

Last Answer : Hydrogen

Description : Total number of elements in periodic table?

Last Answer : 118

Description : The longest period of the periodic table?

Last Answer : Sixth period

Description : The shortest period of the periodic table?

Last Answer : First period

Description : The periodic table is divided into 4 main blocks: they are?

Last Answer : block - elements of group 1 and 2; P block - ele- ments of group 13to 18; D block - elements of group 3 to 12; F block - Lanthanides and Actinides

Description : The right side of the periodic table de- notes?

Last Answer : Non-metals

Description : The left side of the periodic table de- notes?

Last Answer : Metals

Description : Columns are periodic table called?

Last Answer : Groups

Description : The rows in periodic table are called?

Last Answer : Periods

Description : Modern periodic table was discovered by?

Last Answer : Henry Moseley

Description : The periodic table was discovered by?

Last Answer : Dmitri Ivanovich Mendeleev

Description : Modern periodic table contains?

Last Answer : 7 horizontal rows and 18 vertical columns

Description : The modern periodic table is based on?

Last Answer : atomic number

Description : Moseley's periodic table was based on the?

Last Answer : atomic number of elements

Description : Mendeleev's periodic table was based on?

Last Answer : increasing order of atomic mass

Description : On going down in a group in the periodic table, the metallic nature of element

Last Answer : increases.

Description : The incomplete period in the periodic table is

Last Answer : seventh period.

Description : The longest period in the periodic table is

Last Answer : sixth period

Description : The shortest period in the periodic table is

Last Answer : first period.

Description : In the modern periodic table, the elements are arranged in the ascending order of their

Last Answer : atomic number.