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 : 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 : The atomic masses of three elements X, Y and Z having similar chemical properties are 7, 23 and 39 respectively. a) Calculate the average atomic mass of elements X and Z. b) How is the ... this example? d) Give another example of a set of elements which are classified according to this law.
Last Answer : a) The average atomic mass of X and Z = 7 39 2 46 2 23 b) The average atomic mass of X and Z is equal to the atomic mass of Y c) The law illustrated in this example is Dobereiner’s law of triads. d) Another example of Dobereiner’s law is Calcium, Strontium and Barium.
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 : 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 : Law of octaves says that if the chemical elements are arranged according to increasing atomic weight, those with similar physical and chemical properties occur after each interval of elements
Last Answer : 7
Description : The periodicity of repetition of properties in Newland’s law was
Last Answer : eight.
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 : 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 : 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 : Pick up the correct statement from the following: (A) The object of classifying soils is to arrange them into groups according to their properties and behaviour (B) A soil classification system is ... first category of soil classification is based on grain size of the soil (D) All the above
Last Answer : Answer: Option D
Description : According to the American Society of Anesthesiology Physical Status Classification System, a patient with severe systemic disease that is not incapacitating is noted to have physical status ... normal healthy patient d) P2 Classification P2 reflects a patient with mild systemic disease
Last Answer : a) P3 Classification P3 patients are those who have compensated heart failure, cirrhosis, or poorly controlled diabetes, for example.
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 : An arrangement of elements with similar properties placed together is called?
Last Answer : Periodic Table
Description : Why the elements belonging to the same group do have similar chemical properties ?
Last Answer : Why the elements belonging to the same group do have similar chemical properties?
Description : Which of the following pair of elements has similar properties ?
Last Answer : Which of the following pair of elements has similar properties? a. 13, 31 b. 11, 20 c. 12, 10 d. 21, 33
Description : What elements have similar properties with krypton?
Last Answer : What is the answer ?
Description : For the formation of cell-components the elements required are a. Nitrogen b. Oxygen c. Sulphur d. All of these
Last Answer : Ans: D
Description : Which one of the following elements is polyatomic? (1) Argon (2) Sodium (3) Sulphur (4) Oxygen
Last Answer : (3) Sulphur Explanation: The term polyatomic is used for a molecule or an ion which contains either two or more than two atoms.
Description : Two elements which can form a large number of compounds are (1) Carbon and Hydrogen (2) Carbon and Nitrogen (3) Carbon and Oxygen (4) Carbon and Sulphur
Last Answer : (1) Carbon and Hydrogen Explanation: The carbon-hydrogen bond (C-H bond) is a bond between carbon and hydrogen atoms that can be found in many organic compounds. Compound classes ... bonds are alkanes, alkenes, alkynes, and aromatic hydrocarbons. Collectively they are known as hydrocarbons.
Description : About 98 percent of the mass of every living organism is composed of just six elements including carbon, hydrogen, nitrogen, oxygen and (a) sulphur and magnesium (b) magnesium and sodium (c) calcium and phosphorus (d) phosphorus and sulphur.
Last Answer : (d) phosphorus and sulphur.
Last Answer : Carbon and Hydrogen
Description : The names of the scientists; Newlands; Mendeleev; and Meyer are associated with the development of?
Last Answer : periodic table of contents
Description : State Newland’s law of Octaves.
Last Answer : New land law of octaves states that “When elements are arranged in the order of increasing atomic mass, the properties of the eighth element (starting from any given element) are a repetition of the properties of the first element”
Description : NEWLAND’S OCTAVES
Last Answer : After failure of Dobereiner's triads, newland's octaves classification was done. 56 elements were discovered. Elements are arranged in an increasing order of their atomic masses. Every ... later several elements were known. It not includes inert gases because they were not discovered.
Description : what is Newlands' law of octaves? Explain with example
Last Answer : what is Newlands' law of octaves? Explain with example
Description : Why did Newlands place Hydrogen in the that octave?
Last Answer : Feel Free to Answer
Description : Which one of the following best defines the word allotropes ? A Different structural forms of an element B A pair of substances that differ by H+ C Elements that possess properties intermediate between ... a specific number of neutrons E The different phases (solid, liquid or gas) of a substance
Last Answer : A Different structural forms of an element
Description : If living cells, similar to those found on earth, were found on anotyher planet, where there was no oxygen, which cell organelle would most probably b
Last Answer : If living cells, similar to those found on earth, were found on anotyher planet, where ... . Golgi apparatus C. Mitochondria D. Endoplasmic Reticulum
Description : Oxygen is always divalent while sulphur can form 2, 4 and 6 bonds because
Last Answer : Oxygen is always divalent while sulphur can form 2, 4 and 6 bonds because A. High ... Vacant d-orbitals in the valency shell of Sulphur
Description : The similarity in the properties of a group of elements is because they have same number
Last Answer : of outer electrons.
Description : Steels with high carbon equivalent have poor Weldability, because in these steels during welding (A) Carbon and other alloying elements get oxidised from the weld pool (B) Excessive ferrite forms in the ... of carbon and other element occurs in the weld pool leading to poor properties of the weld
Last Answer : (C) Martensite forms in the heat affected zone leading to poor toughness/ductility of the weld
Description : Lane and Garton classification of petroleum is based on its (A) Composition (B) Specific gravity (C) Optical properties (D) Viscosity
Last Answer : (B) Specific gravity
Description : Heating rubber with sulphur for the bet- terment of its properties ike tensile steqasbh: hardness; elasticity etc. is called as?
Last Answer : Vulcanisation
Description : Washing of coal (A) Reduces its sulphur and ash content (B) Controls its ash fusibility and increases its calorific value (C) Improves its coking properties (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Washing of coal (A) Reduces its ash & sulphur content (B) Improves its coking properties (C) Increase the fusion point of its ash by removing chlorine compounds (D) All (A), (B) and (C)
Description : Which of the following gradients exerts maximum influence on properties of steel? (A) Iron (B) Carbon (C) Manganese (D) Sulphur
Last Answer : Answer: Option B
Description : What element has similar to sulphur?
Last Answer : Need answer
Description : Why was the system of classification of elements into triads not found suitable? -Science
Last Answer : it is because all the elements discovered at that time could not be classified into triads.
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 : First attempt of classification of elements was made by
Last Answer : Dobereiner.c
Description : What is the significance of atomic number in the modern classification of elements?
Last Answer : In the modern classification, elements are arranged in the increasing order of their atomic numbers.
Description : What was the Mendeleev’s basis for classification of elements?
Last Answer : Mendeleev’s classification is based on atomic mass.
Description : Give reason: Classification of elements as metals and non-metals is justified but not satisfactory.
Last Answer : Classification of elements as metals and non-metals is justified because there are more common characteristics in both the groups but it is not satisfactory because each metal or non-metal have completely different properties.
Description : Give reason: Classification of elements on the basis of states of matter cannot be justified.
Last Answer : Classification on the basis of states of matter cannot be justified because for example bromine and mercury are liquids at room temperature, they cannot be placed in the same group.
Description : What is the need for periodic classification of elements?
Last Answer : When elements are classified such that they have the same properties, study of large number of elements is reduced to study of few groups of elements.
Description : Ch 5 – Periodic Classification of Elements
Last Answer : Ch 5 – Periodic Classification of Elements notes
Description : …… refers to the disparity of classification of person according to their knowledge of ICT and without it. -Technology
Last Answer : Digital divide refers to the disparity of classification of a person according to their knowledge of ICT and without it.
Description : $ Classification based on the evolutionary relationships among the organisms is called phylogenetic classification. ! According to Binomila Nomenclatu
Last Answer : $ Classification based on the evolutionary relationships among the organisms is called phylogenetic classification. ! ... If both As and R are wrong.
Description : What are the classification of action according to norms of morality?
Last Answer : moral(good) immoral(bad)and amorral (indifferent)