Description : The radioactive nuclide `._(90)^(234) Th` shows two successive `beta-` decay followed by one `alpha-` decay. The atomic number and mass number respect
Last Answer : The radioactive nuclide `._(90)^(234) Th` shows two successive `beta-` decay followed by one `alpha-` ... is: A. 92234 B. 94230 C. 90230 D. 92230
Description : In the sun, helium is produced from hydrogen by: w) radioactive decay x) disintegration y) fission z) fusion
Last Answer : ANSWER: Z -- FUSION
Description : In the disintegration of a radioactive element, `alpha` and `beta`-particles are evolved from the nucleus: `._(0)^(1)n to ._(1)^(1)H + ._(-1)^(0)e` +
Last Answer : In the disintegration of a radioactive element, `alpha` and `beta`-particles are evolved from ... of `gamma`-radiations may yield nuclear isomer
Description : In the disintegration of a radioactive element, `alpha`- and `beta`-particles are evolved from the nucleus. `._(0)n^(1) rarr ._(1)H^(1) + ._(-1)e^(0)
Last Answer : In the disintegration of a radioactive element, `alpha`- and `beta`-particles are evolved from the nucleus. `._(0 ... C. `2 alpha, 2 beta` D. `n beta`
Last Answer : In the disintegration of a radioactive element, `alpha`- and `beta`-particles are evolved from the ... C. decreases by 2 unit D. remains unaffected
Last Answer : In the disintegration of a radioactive element, `alpha`- and `beta`-particles are evolved from the nucleus. `._(0) ... in A. IIA B. IA C. IIB D. IVB
Last Answer : In the disintegration of a radioactive element, `alpha`- and `beta`-particles are evolved from the nucleus. ... , beta, beta` D. `beta, gamma, alpha`
Description : Pick out the wrong statement. (A) α-particle emission from a radioactive element makes it electrically negative (B) β-particle emission from a radioactive element makes it electrically ... ) The disintegration constant of a radioactive isotope is independent of pressure, temperature or concentration
Last Answer : (C) A radioactive element having a half life period of 20 years will completely disintegrated in 40 years
Description : The element extracted from radioactive disintegration of radium?
Last Answer : Radon
Description : The disintegration rate of a radioactive element (A) Progressively increases (B) Progressively decreases (C) Remains constant throughout (D) May increase or decrease depending on the material
Last Answer : (B) Progressively decreases
Description : Pick out the wrong statement. (A) The disintegration rate of a radioactive substance cannot be increased by heating it (B) Electrons have negligible mass and unit negative change (C) Deuterium atom has one proton and two neutrons in its nucleus (D) Cadmium is capable of absorbing neutrons
Last Answer : (C) Deuterium atom has one proton and two neutrons in its nucleus
Description : (2) it is lighter than air Explanation: Helium is the second lightest element and is the second most abundant element in the observable universe, being present at about 24% of the total elemental mass ... elements combined. A well-known but minor use is as a lifting gas in balloons and airships
Last Answer : Ammonial is a mixture of – (1) aluminium powder and ammonium nitrate (2) aluminium powder and ammonium chloride (3) aluminium powder and ammonium sulphate (4) aluminium powder and potassium nitrate
Description : Assertion : In a radioactive disintegration, an electron is emitted by the nucleus. Reason : Electrons are always present inside the nucleus.
Last Answer : Assertion : In a radioactive disintegration, an electron is emitted by the nucleus. Reason : Electrons are ... both (A) and (R ) are incorrect.
Description : Which of the following is the man-made radioactive disintegration series?
Last Answer : Which of the following is the man-made radioactive disintegration series? A. Thorium series B. Neptunium series C. Uranium series D. Actinium series
Description : Starting from radium, the radioactive disintegration process terminates when the following is obtained a)radon b)lead c)uranium d)thorium
Last Answer : Starting from radium, the radioactive disintegration process terminates when the following is obtained a)radon b) ... . radon C. radium A D. radium B
Description : Neutrons are obtained by (a) Bombardment of radium with aparticles (b) Bombardment of beryllium with b-particles (c) Radioactive disintegration of uranium (d) None of the above
Last Answer : Ans:(c)
Description : β-rays emission in radioactive disintegration is always accompanied by the emission of (A) γ-rays (B) α-rays (C) Neutrons (D) None of these
Last Answer : (A) γ-rays
Description : Radioactive disintegration of uranium ultimately results in formation of (1) radium (2) thorium (3) polonium (4) lead
Last Answer : lead
Description : Radioactive isotope of Uranium used in Nuclear Bomb is ? A.92 U 235 (Answer) B.92 U 234 C. 92 U 233 D. 92 U 238
Last Answer : A.92 U 235 (Answer)
Description : In which of the following groups, are the elements written in the descending order of their respective atomic weights? (a) Nitrogen, carbon, oxygen, hydrogen (b) Oxygen, argon, nitrogen, hydrogen (c) Oxygen, nitrogen, helium, hydrogen (d) Oxygen, nitrogen, helium, bromine
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
Last Answer : A radioactive element `X` has an atomic number of 100. It decays directly into an element `Y` which decays ... of 100 D. Z has an atomic number of 99
Description : The atomic number of a radioactive element is not changed, when it emits __________ rays. (A) α (B) β (C) γ (D) α & β
Last Answer : (C) γ
Description : The new nucleus formed after β-decay of a radioactive element has (A) Less atomic number (B) Less atomic weight (C) More atomic number (D) More atomic weight
Last Answer : (A) Less atomic number
Description : The isotope used for the production of atomic energy is - (1) U-235 (2) U-238 (3) U-234 (4) U-236
Last Answer : (1) U-235 Explanation: U235 is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope U238 it is fissile, i.e., it can sustain fission chain reaction. It ... critical, and the mass of U required to produce the critical condition is said to be a critical mass.
Description : The isotope used for the production of atomic energy is (1) U-235 (2) U-238 (3) U-234 (4) U-236
Last Answer : U-235
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 : (A) Nuclear isomers have same atomic number and same mass number but with different radioactive properties. `U_((A))` and `U_((Z))` are nuclear isomer
Last Answer : (A) Nuclear isomers have same atomic number and same mass number but with different radioactive properties. `U_ ... both (A) and (R ) are incorrect.
Description : A nuclide has mass number (A) and atomic number (Z). During a radioactive process if: (A) both A and Z decrease, the process is called `alpha`-decay (
Last Answer : A nuclide has mass number (A) and atomic number (Z). During a radioactive process if: (A) both A and Z decrease, ... 4 C. 1,3, and 4 D. 1,2, and 4
Description : What is the relative atomic mass of helium ?
Last Answer : The relative atomic mass of helium is four.
Description : Which element forms compounds with all others elements except except helium neon and argon?
Last Answer : i believe the answer is flourine.
Description : The process of changing of one element into another is called (a) radioactive decay (b) transmutation of the elements (c) covalent bond formation (d) hybridization
Last Answer : Ans:(b)
Description : Radon differs from other naturally radioactive elements in which one of the following ways. Is it because radon w) is extremely radioactive x) decays into the element radium y) is a noble gas z) is as chemically active as fluorine
Last Answer : ANSWER: Y -- IS A NOBLE GAS
Description : Which of the following may be used to measure the rate of nuclear disintegration? (A) Geiger-Muller Counter (B) Cyclotron (C) Cold chamber (D) Mass spectrograph
Last Answer : (A) Geiger-Muller Counter
Description : Which one is radioactive in nature? (A) Helium (B) Deuterium (C) Heavy hydrogen (D) Tritium
Last Answer : (D) Tritium
Description : Atomic number of an element gives (a) The number of protons in its atom (b) The number of nucleons in its atom (c) The weight of the atom of the element (d) The total number of elementary particles in its atom
Last Answer : Ans:(a)
Description : What element has an atomic number lower than that of aluminum and one less valence electron than group 16 elements?
Last Answer : Nitrogen
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 : 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 : I will be describing a chemical element. Try to identify it with the fewest number of clues. This chemical element is a silver-white metal, with bluish tinge, capable of taking a high polish. T element ... crust and used to make drink cans. The atomic number of this element is 13. Name t element.
Last Answer : ANSWER: ALUMINUM
Description : What is the atomic number of helium ?
Last Answer : Helium has atomic number two.
Description : Helium gas is filled in ballons because (1) its atomic number is 2 (2) it is lighter than air (3) it is one of the constitutents of water (4) it is a noble gas
Last Answer : it is lighter than air
Description : The composition of sun is 90 % Hydrogen and Helium and Heavy metals ratio is:
Last Answer : 7.8 %
Description : There are two elements calcium (atomic number 20) and argon (atomic number 18) The mass number of both the elements is 40. They are therefore known as (a) isotones (b) isochores (c) isobars (d) isotopes
Description : When the difference between mass number and atomic number of atoms of two or more elements are same, the atoms are termed as (A) Isomers (B) Isotopes (C) Isobars (D) Isotones
Last Answer : (D) Isotones
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 : 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 : Among the elements of the 3rd period from Na to Ar, pick out the element: (L-2) (a). with highest first ionization enthalpy. (b). with largest atomic radius. (c). that is most reactive non-metal. (d). that is most reactive metal.
Last Answer : (a). Ar has highest first ionization enthalpy. (b). Na has large atomic radius (covalent radius). (c). Cl is more reactive non-metal in 3rd period. (d). Na is most reactive metal in third period.
Description : What are isobars? (1) Elements with same atomic number but different mass number (2) Elements with different atomic number but same mass number (3) Elements with different atomic number and different mass number (4) Elements with same atomic number and same mass number
Last Answer : (2) Elements with different atomic number but same mass number Explanation: Isobars are atoms of different chemical elements that have the same number of n cleons. Correspondingly, isobars differ in atomic number (number of protons) but have the same mass number.
Description : Elements having same mass number and different atomic number are known as?
Last Answer : Isobars Eg: calcium — 40; Argon - 40