Description : Compound A is extracted from a solution of A + B into a pure solvent S. A Co-current unit is used for the liquid-liquid extraction. The inlet rate of the solution containing A is 200 moles of B/hr.m2 and the ... extraction achieved in the unit is (A) 25% (B) 50% (C) 70% (D) 90%
Last Answer : (B) 50%
Description : What is salts chemical formular?
Last Answer : Common salt (Sodium Chloride) has the formula NaCl.
Description : Formular for calculating probability under law of compliment?
Last Answer : P(A)=1-(A)
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 : The density of lead is 12 grams per cm3. A lead brick has a mass of 1.5 kilograms. Its dimensions are 10 cm by 5 cm by 4 cm. Is it: w) More than 75% hollow x) Between 50 and 75% hollow y) Between 25 and 50% hollow z) Between 0 and 25% hollow
Last Answer : ANSWER: Y -- BETWEEN 25 AND 50% HOLLOW
Description : Two element X (at. Mass = 75) and Y (at. Mass = 16) combine to give a compound having 75.8% of X. the formula of the compound is :-
Last Answer : Two element X (at. Mass = 75) and Y (at. Mass = 16) combine to give a compound having 75.8% of X. the formula of ... ` C. `X_(2)Y_(2)` D. `X_(2)Y_(3)`
Description : The half-life of an isotope of an element is 5 days. The mass of a 10 gram sample of this isotope remaining after 20 days is: w) 0.312 grams x) 0.625 grams y) 1.25 grams z) 2.50 grams
Last Answer : ANSWER: X -- 0.625 GRAMS
Description : Simplest atom (based on atomic mass) is that of?
Last Answer : Hydrogen
Description : `3.011 xx 10^(22)` atoms of an element weight 1.15 g. The atomic mass of the element is :-
Last Answer : `3.011 xx 10^(22)` atoms of an element weight 1.15 g. The atomic mass of the element is :- A. 10 amu B. 2.3 amu C. 35.5 amu D. 23 amu
Description : An element X has a mass number 4 and atomic number 2. Write the valency of this element? -Science
Last Answer : Mass number = 4 Atomic number = 2 X is Helium. It has 0 valency and it will not react with any other atom because it has its outer shell filled.
Description : How many neutrons does element x have if its atomic number is 22 and its mass number is 84?
Last Answer : Need answer
Description : Two elemets `X(` atomic weight `=75)` and `Y(` atomic weight `=16)` combine to give a compound having `75.8%` X.` The formula of the compound is
Last Answer : Two elemets `X(` atomic weight `=75)` and `Y(` atomic weight `=16)` combine to give a compound having `75.8%` X.` ... C. `X_(2)Y_(2)` D. `X_(2)Y_(3)`
Last Answer : Two elemets `X(` atomic weight `=75)` and `Y(` atomic weight `=16)` combine to give a compound having `75.8%` X. ... B. `xy_(2)` C. xy D. `x_(3)y_(3)`
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 : Consider an ideal solution of components A and B. The entropy of mixing per mole of an alloy containing 50% B is (A) R ln 2 (B) -R ln 2 (C) 3 R ln 2 (D) -3R ln 2
Last Answer : (A) R ln 2
Description : A bacterial colony containing DNA made up of 100% N15 nitrogen bases is allowed to replicate in a medium containing N14 bases. After one round of replication the result would be a) All individuals ... Only 50% individuals would be hybrids d) All individuals would have DNA made up of 100% N14
Last Answer : b) All individuals will be hybrids
Description : Black cotton soils are a) Heavy clay soils varying from clay to Loam, with clay content of 40 to 50% formed by decomposition of rocks by long continued weathering* b) Compacted and ... underneath d) Dark brown earthy materials formed due to partial or complete decomposition of vegetable matter
Last Answer : a) Heavy clay soils varying from clay to Loam, with clay content of 40 to 50% formed by decomposition of rocks by long continued weathering*
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 : When a radioisotope undergoes beta minus decay, does its atomic number: w) increase x) decrease y) remain the same z) vary depending on the element involved
Last Answer : ANSWER: W -- INCREASE
Description : Simplest binary organic compounds containing carbon and hydrogen only are called
Last Answer : hydrocarbons.
Description : At permanent wilting point pF value is a. 2.2 b. 6 c. 4.2 d. 10
Last Answer : c. 4.2
Description : A 200 V, 50 Hz inductive circuit takes a current of 10 A at 30 degree lagging pf, what is the inductive reactance of the circuit? (A) 17.8 Ω (B) 100 Ω (C) 178 Ω (D) 10 Ω
Last Answer : D
Description : Which of the following statements regarding angiogenesis are true? a. Angiogenesis is a seminal biologic event with clinical relevance limited to its effect upon tumor growth b. C-X-C ... c. PF-4 has angiogenic properties d. Sites of atherosclerosis demonstrate chronic angiogenic activity
Last Answer : Answer: b, d An important component of tissue repair and wound healing is the process of angiogenesis. This normal, physiologic process is a local, transient event which is ... between these factors may govern overall angiogenic potential in a variety of physiological and pathophysiological states
Description : What is the molecular mass of a gas that effuses through a small hole at twice the rate as oxygen gas at the same temperature. (The molecular mass of O2 is 32.) w) 8.0 atomic mass units x) 16 atomic mass units y) 48 atomic mass units z) 64 atomic mass units
Last Answer : ANSWER: W -- 8.0 ATOMIC MASS UNITS
Description : In Rutherford's experiment involving the deflection of alpha particles by atomic nuclei, the fact that some of the alpha particles bombarding the thin gold foil were back-scattered, led to one of the ... its nucleus z) the nucleus of a gold atom occupies nearly the entire space of the atom
Last Answer : ANSWER: Y -- MOST OF THE MASS OF A GOLD ATOM IS IN ITS NUCLEUS
Description : Which of the following elements is found in the earth's crust as both a native element and as a compound? w) argon x) copper y) chlorine z) silicon
Last Answer : ANSWER: X -- COPPER
Description : 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
Last Answer : For an element , if atomic number (Z) and mass number (A) are 29 and 63 respectively . Then the number of protons ... C. 29 , 34 ,29 D. 29 , 29 , 29
Description : A radioactive element A on disintegration gives two elements B and C. If B is helium and C is the element of atomic number 90 and atomic mass 234, the
Last Answer : A radioactive element A on disintegration gives two elements B and C. If B is helium and C is the element of atomic ... )^(234)Th` D. `._(91)^(234)Pa`
Description : Why is the atomic mass of an element is usually not given as a whole number even though each individual atom of the element has a whole number of protons and neutrons.?
Last Answer : It's the electrons that throw it off.
Description : What is the Average atomic mass an element?
Last Answer : The average atomic weight (not mass for elements) of a chemicalelement is calculated taking into account the isotopic compositionof this element and the atomic masses (not weight for isotopes) ofthese isotopes.
Description : If an atomic number of an element is 6 and its mass is 14 how many neutrons are contained in the nucleus?
Last Answer : jjjj
Description : Which one of the following is the most characteristic property of an element? (a) Density (b) Boiling point (c) Mass number (d) Atomic number
Last Answer : Ans:(d)
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
Description : All isotopes of the same element have (1) different atomic numbers and different atomic mass (2) different atomic numbers and the same atomic mass (3) the same atomic number but different atomic masses (4) the same atomic number and the atomic mass
Last Answer : (3) the same atomic number but different atomic masses Explanation: Isotopes are forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei. So they have the same atomic number, but differ in relative atomic mass.
Description : An atom of an element has atomic number 17 and mass number 36. The number of neutrons in its nucleus is– (1) 17 (2) 19 (3) 36 (4) 53
Last Answer : (2) 19 Explanation: Mass Number = number of protons (atomic number) + nu.sriber of neutrons. So as per the question, 36= number of neutrons + 17. Number of neutrons= 36 -17= 19
Description : The umber of neutrons present in an element having mass number 226 and atomic number 88 is– (1) 88 (2) 138 (3) 314 (4) 50
Last Answer : (2) 138 Explanation: The mass number is a count of the number of particles in an atom's nucleus which is made up of protons and neutrons. In other words, Mass Number = Number of Protons + Number of Neutrons. ... of an element, 226 = 88 + number of Neutrons. So, the number of neutrons= 226 - 88= 138.
Description : An Element Atomic number 17 and mass number 36, then number of neutrons present in it–
Last Answer : 19
Description : 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
Last Answer : (A) 1
Description : The atomic mass of an element is fractional, because (A) Of uncertainty principle (B) It may have isobars (C) It contains neutrons (D) It may have isotopes
Last Answer : (D) It may have isotopes
Description : Isotopes of an element have the same (A) Number of neutrons (B) Mass number (C) Electronic configuration (D) Atomic weight
Last Answer : (C) Electronic configuration
Description : Atoms of the same element having same atomic number and different mass number are known as?
Last Answer : Isotopes
Description : 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?
Last Answer : Atomic mass of A=80 Atomic mass of B=120 A C 2 Atomic mass of B = 80 C 2 120x2 80 C 120 240 C 80 C 240 80 C 160
Description : An Element Atomic number 17 and mass number 36, then number of neutrons present in it
Description : All isotopes of the same element have ______ (1) different atomic numbers and different atomic mass (2) different atomic numbers and the same atomic mass (3) the same atomic number but different atomic masses (4) the same atomic number and the atomic mass
Last Answer : the same atomic number but different atomic masses
Description : An atom of an element has atomic number 17 and mass number 36. The number of neutrons in its nucleus is (1) 17 (2) 19 (3) 36 (4) 53
Description : The number of neutrons present in an element having mass number 226 and atomic number 88 is : (1) 88 (2) 138 (3) 314 (4) 50
Last Answer : 138
Description : (a) Explain the formation of ionic compound CaO with electron dot structure. Atomic number of calcium and oxygen are 20 and 8 respectively. (b) Name the constituent metals of bronze. -Chemistry
Last Answer : (b) Bronze is made up of copper and tin
Description : Electronic configuration of Element Atomic number 20 is –
Last Answer : 2, 8, 8, 2
Description : The nitrogen containing compound produced in the reaction of `HNO_(3)` with `P_(4)O_(10)`
Last Answer : The nitrogen containing compound produced in the reaction of `HNO_(3)` with `P_(4)O_(10)` A. ... bond D. react with Na metal producing a brown gas