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 average atomic mass of elements X and Z compare with the atomic mass of element Y? c) Which law of classification of elements is illustrated by this example? d) Give another example of a set of elements which are classified according to this law.

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 average atomic mass of elements X and Z compare with the atomic

mass of element Y?

c) Which law of classification of elements is illustrated by this example?

d) Give another example of a set of elements which are classified according to this

law.
by

1 Answer

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.
by

Related questions

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 the - (1) Law of Pentamates (2) Law of musical notes (3) Law of Octaves (4) None of the above

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’.

Lithium, sodium and potassium form a Dobereiner’s triad. The atomic masses of lithium and potassium are 7 and 39 respectively. Predict the atomic mass of sodium. -Science

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Last Answer : Lithium, sodium and potassium form a Dobereiner's triad. The atomic masses of lithium and potassium are 7 and 39 respectively. Predict the atomic mass of sodium. Therefore, the atomic mass of sodium = average of the atomic mass of lithium and potassium = 23.

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

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Last Answer : 7

In a triad A, B and C, the atomic masses of A and B are 80 and 120 respectively. What is the atomic mass of element C?

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Last Answer : There are 6 elements between X and Y

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Description : The mass spectrograph directly yields a value for which one of the following? w) mass of a photon x) mass of a neutron y) masses of isotopes of elements z) mass to charge ratio of ions

Last Answer : ANSWER: Z -- MASS TO CHARGE RATIO OF IONS

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Description : Consider the isotopes of carbon, C-12 and C-14. Would you place them in different slots because their atomic masses are different or would you place them in the same position because their chemical properties are the same?

Last Answer : Isotopes are not placed according to their atomic mass but they are all placed in the same position as they have the same atomic number.

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Description : According to Newton's law of universal gravitation, any two particles of finite mass attract one another with a force which is A. Inversely proportional to the product of their masses and ... the product of their masses and inversely proportional to the square of their distance apart

Last Answer : Directly proportional to the product of their masses and inversely proportional to the square of their distance apart

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38. Consider three sets \( X, Y \) and \( Z \) having 6,5 and 4 elements respectively. A.11 these 15 elements are distinct. Let \( S=(X-Y) \cup Z \). How many proper subsets does \( S \) have?(a) 255(b) 256(c) 1023(d) 1024

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For an element , if atomic number (Z) and mass number (A) are 29 and 63 respectively . Then the number of protons , neutrons and electrons respectivel

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If`N_(1),N_(2),N_(3),……`are the number of molcules with molecular masses `M_(1),M_(2),M_(3),…`respectively ,then mass average molar mass is expressed

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The ratio of neutrons to protons of an element having a mass number and atomic number of 80 and 40 respectively is (A) 1 (B) 0.5 (C) 2 (D) 4

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The binding energy of a nucleus is defined as one of the following. Is this definition: w) the energy equivalent to its mass x) the mass difference between its neutrons and protons y) the energy needed to remove a neutron from the nucleus z) the difference between the mass of the nucleus and the sum of the masses of its protons and neutrons

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Three pipes P, Q and R can fill a tank from empty to full in 40 minutes, 15 minutes, and 30 minutes respectively. When the tank is empty, all the three pipes are opened. P, Q and R discharge chemical solutions X, Y and Z respectively. What is the proportion of the solution Y in the liquid in the tank after 5 minutes? a) 8 / 15 b) 7 / 15 c) 8 / 17 d) 6 / 13 e) 8 / 13

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Which of the following is the same for both radioactive iodine and stable iodine? w) number of neutrons x) mass number y) half-life z) chemical properties

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The person in 1815 who suggested in that elements can be classified on the basis of atomic mass was

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Description : An atom of an element with mass number 23 and atomic number 11 will have- (1) 11 neutrons, 12 protons and 11 electrons (2) 11 protons, 12 neutrons and 11 electrons (3) 11 protons, 12 electrons and 11 neutrons (4) 23 protons and 11 electrons

Last Answer : (2) 11 protons, 12 neutrons and 11 electrons

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 those of metals and nonmetals D Atoms of a given atomic number that have a specific number of neutrons E The different phases (solid, liquid or gas) of a substance

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How do the decimal places on the atomic masses of elements realate to isotopes?

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How do the decimal places on the atomic masses of elements realate to isotopes?

Description : How do the decimal places on the atomic masses of elements realate to isotopes?

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It is important to balance the chemical equations to satisfy the law of conservation of mass. Which of the following statements of the law is incorrect? (a) The total mass of the elements present in the reactants is equal to the total mass of the elements present in the products. (b) The number of atoms of each element remains the same, before and after a chemical reaction. (c) The chemical composition of the reactants is the same before and after the reaction (d) Mass can neither be created nor can it be destroyed in a chemical Reaction.

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X, Y & Z rent a pasture. X puts 20 cows for 5 months , Y puts 24 cows for 7 months and Z puts 30 cows for 3 months for grazing. If the rent of the pasture is Rs. 150, how much must z pay as his share of rent? A) 32 B) 39.65 C) 37.70 D) 35.20

Description : X, Y & Z rent a pasture. X puts 20 cows for 5 months , Y puts 24 cows for 7 months and Z puts 30 cows for 3 months for grazing. If the rent of the pasture is Rs. 150, how much must z pay as his share of rent? A) 32 B) 39.65 C) 37.70 D) 35.20

Last Answer : Answer: C) X : Y : Z = 20* 5 : 24* 7 : 30 * 3 = 100 : 168 : 90 =50 : 84 : 45 Therefore Z’s rent = Rs (150 * 45 / 179) = Rs.(6750/179) Rs.37.70

Calculate the mass loss in the following: `._(1)^(2)H + ._(1)^(3)H to ._(2)^(4)He + ._(0)^(1)n` given the masses: `._(1)^(2)H = 2.014` amu, `._(1)^(3)

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The Russian chemist who said that the properties of elements are periodic function of their atomic mass is

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Last Answer : Dmitri Mendeleev.

The atomic weight and atomic number of an element are A and Z respectively. What is the number of neutrons in the atom of that element? (A) A + Z (B) A - Z (C) A (D) Z

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Last Answer : (B) A - Z

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

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Why the elements belonging to the same group do have similar chemical properties ?

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Last Answer : Why the elements belonging to the same group do have similar chemical properties?

Properties of elements X: (i) Its amide is used as a reducing agent (ii) Its amalgam is used as reducing agent Properties of element Y: (i) It is an o

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Properties of elements X: (i) Its amide is used as a reducing agent (ii) Its amalgam is used as reducing agent Properties of element Y: (i) It is an o

Description : Properties of elements X: (i) Its amide is used as a reducing agent (ii) Its amalgam is used as reducing agent Properties of element Y: (i) It is an o

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Properties of elements X: (i) Its amide is used as a reducing agent (ii) Its amalgam is used as reducing agent Properties of element Y: (i) It is an o

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Two persons of masses 55 kg and 65 kg respectively, are at the opposite ends of a boat. The length of the boat is 3.0 m and weighs 100 kg. The 55 kg man walks up to the 65 kg man and sits with him. If the boat is in still water the centre of mass of the system shifts by

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What element has similar chemical properties to phosphorus?

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How do you calculate average atomic mass?

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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?

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Three materials X, Y and Z having relative permittivity 2.5, 3.0 and 4.0 respectively are used in a single core

Description : Three materials X, Y and Z having relative permittivity 2.5, 3.0 and 4.0 respectively are used in a single core cable. The materials on inner most and outer most layer respectively should be (a) X and Y (b) Y and Z (c) X and Z (d) Z and X 

Last Answer : Answer is option d Because the material with high relative permitivity should be used as the inner most layer of the cable,to withstand with the  high currents flowing in the conductor 

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

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A leaf spring consists of 3 extra full length leaves and 14 graduated length leaves. The maximum force that can act on the spring is 70kN and the distance between eyes of the spring is 1.2m. Width and thickness of the leaves are 100mm and 12mm respectively. If modulus of elasticity is 207000N/mm², calculate the initial nip. (a) 26.8mm (b) 24.9mm (c) 22.5mm (d)23.1mm

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Description : Lenz's law is an example of the law of conservation of one of the following. Is it conservation of: w) mass x) charge y) momentum z) energy

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L. A. Gear's sports shoe line would have been classified as a problem child when it was introduced. Based on this classification, which of the following would have been true according to the product -portfolio matrix? A)High profitability B)High market growth rate C)High market share D)Positive cash flow E)Relatively high sales volume

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If reading AC current with the illustrated device and unsure of the range as a precaution , the first step should be to _________. EL-0047 A. secure power and test for voltage B. disconnect the lead to be tested and connect the meter in series C. connect the meter to measure resistance and use Ohm's law to calculate current D. unable to safely measure current with the device

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A radioactive element `X` has an atomic number of 100. It decays directly into an element `Y` which decays directly into an element `Z`. In both the p

Description : A radioactive element `X` has an atomic number of 100. It decays directly into an element `Y` which decays directly into an element `Z`. In both the p

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