Description : What are the weak metals ?
Last Answer : answer:
Description : (1) they contain free electrons Explanation: Metals typically consist of closepacked atoms, meaning that the atoms are arranged like closely packed spheres. Two packing motifs are common, one ... surrounded by six neighboring atoms. Several metals adopt both structures, depending on the temperature.
Last Answer : 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
Description : Why does metal make a sound when hammered and non-metals not?
Last Answer : Everything makes a sound when hit. Rigid things tend to make more sound because the vibration propagates over the whole shape quickly because the rigid thing is held tightly, so instead of just giving ... -lasting sound at one frequency. Metal is a rigid thing because of its structure. See above.
Description : Which pair of metals constitutes the lightest metal and the heaviest metal, respectively? -Do You Know?
Description : Refining process of impure metals depends upon the differences in properties of the metal. Extraction of Al is usually carried out from its bauxite or
Last Answer : Refining process of impure metals depends upon the differences in properties of the metal. ... . leaching C. liquation D. magnetic seperation
Last Answer : Refining process of impure metals depends upon the differences in properties of the metal. Extraction of Al is usually ... A D. I-D,II-A,III-C,IV-B
Description : Statement-1: Carbon is not used as a reducing agent for the extraction of group 2 metals. Statement-2: Carbon reacts with group 2 metal to give carbid
Last Answer : Statement-1: Carbon is not used as a reducing agent for the extraction of group 2 metals. Statement ... Statement-1 is false but Statement -2 is true
Description : Metals of high purity are obtained by zone refining. Impurities are more soluble in melt in pure metal.
Last Answer : Metals of high purity are obtained by zone refining. Impurities are more soluble in melt in pure ... Statement-1 is false but Statement -2 is true
Description : Van Arkel method of purification of metals involves converting the metal to
Last Answer : Van Arkel method of purification of metals involves converting the metal to A. Volatile ... stable compound D. non-volatile unstable compound
Description : One of the following metals froms a volatile corbony1 compound and this property is taken advantage of its extraction. This metal is
Last Answer : One of the following metals froms a volatile corbony1 compound and this property is taken advantage of its ... . Nickel B. Iron C. Cobalt D. Vanadium
Last Answer : Van Arkel method of purification of metals involves converting the metal to A. Volatile stable ... . Volatile unstable compound D. None of these
Description : Can precious metals be found outdoors using metal detectors.?
Last Answer : I have researched this topic and found that you can indeed find precious metals when using a metal detector. These metal detectors will detect items such as silver, iron, metal, gold and platinum.
Description : Consider the following statements: 1. Mercury metal exists as a liquid at room temperature. 2. The property of metals by which they can be beaten into thin sheets is called malleability 3. Neutral fats such as butter and vegetable oils ... b) 1, 3 and 4 only (c) 2, 3 and 4 only (d) 1, 2 and 3 only
Last Answer : Ans:(d)
Description : Which of the following statements about the physical properties of metal is not correct? (a) All metals are solid except mercury (b) Most metals are hard except sodium and potassium (c) Metals are not malleable (d) Most metals are ductile
Last Answer : Ans:(c)
Description : Which of the following metal forms amalgam with other metals?
Last Answer : Mercury
Description : Which pair of metals constitutes the lightest metal and the heaviest metal, respectively?
Last Answer : Lithium and osmium
Description : The metal known as King of metals?
Last Answer : Gold
Description : Which of the following is universally employed as the low expansion metal in the bimetallic thermometer, which is an iron-nickel alloy containing 36% nickel and has very low co-efficient of expansion (1/20th of ordinary metals) ? (A) Invar (B) Constantan (C) Chromel (D) Alumel
Last Answer : (A) Invar
Description : Which of the following metals in not used for coating of the base metal to guard it against corrosion? (A) Lead (B) Cadmium (C) Magnesium (D) Aluminium
Last Answer : (C) Magnesium
Description : Give reason: a) Metals are electropositive. b) Non-metals are electronegative. c) Even though hydrogen is a non-metal, it is electropositive. d) Sodium is electropositive.
Last Answer : a) Metals are electropositive. Electropositive element has the tendency to lose electrons and form cation.Metals are electron donors. Hence they are electropositive. b) Non-metals are ... is electropositive because donates electrons from last orbit to another element and becomes electropositive.
Description : Give reason: Even though silicon is a non-metal it resembles metals in its properties.
Last Answer : When red hot silicon reacts with steam, it liberates hydrogen. Even when metals like hot iron, zinc or magnesium react with steam, they liberate hydrogen with their respective metal oxides. Hence silicon resembles metals in some properties.
Description : During neutralization reaction acids react with ........to form ........and water. (a) Metals ,Gas (b) Bases, Salt (c) Non-Metal , Salt (d)Acids ,Salts
Last Answer : (b) Bases, Salt
Description : Pick out the wrong statement about coating/electroplating of metals. (A) Phosphate coating is used as an excellent base for paints & enamels (B) Phosphate coating is less corrosion resistant than ... coating metal is made the anode (D) Calorising is the process of coating steel with chromium
Last Answer : (D) Calorising is the process of coating steel with chromium
Description : Brazing filler metal used for joining steel plates (A) Melts below the melting points of base metals (B) Melts below 300°C (C) Is copper phosphorous alloy
Last Answer : (A) Melts below the melting points of base metals
Description : Electrometallurgical methods of metal extraction is normally used for those metals (A) Whose oxide/ore is not reduced by carbon (B) Which fall in the category of alkali & alkaline earth metals (C) Which stands higher in the electrochemical series of the metal (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : With increase in impurities in metals, their corrosion resistances (A) Increase (B) Decrease (C) Remain same (D) May increase or decrease; depending on the type of metal
Last Answer : (B) Decrease
Description : In connection with corrosion of metals, passivation is the process that (A) Intensifies deterioration (B) Changes the composition of the metal (C) Inhibits further deterioration (D) None of these
Last Answer : (C) Inhibits further deterioration
Description : Brazing is the joining of metals (A) Without melting the base metal (B) With a non-ferrous filler (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : Option C
Description : Pick out the wrong statement. (A) Copper is the metal having the highest electronic conductivity (B) Hardenability & Weldability of metals are inversely related (C) Covalent bonding formed by ... all semiconductor materials (D) Glass transition temperature applies to 'polymers' but not to 'glasses'
Last Answer : Option A
Description : Pick out the wrong statement about the machinability of metals. Machinability of a metal (A) Decreases with increase in strain hardening tendencies (B) Decreases with increase in hardness, in general (C) Depend on the composition, microstructure and physical & mechanical
Description : Metals are generally hard, which of the following metal is an exception and can be cut with a knife? a) iron b)sodium c)gold d)magnesium
Last Answer : b)sodium
Description : Rohan had learnt that non-metals on beating with hammer are generally broken into pieces. Which of the following is a non-metal? a) iron nail b)aluminium wire c)copper wire d)piece of coal
Last Answer : d)piece of coal
Description : In which of the following welding methods, the molten metal is poured for joining the metals ? (a) Gas welding (b) Thermit welding (c) TIG welding (d) Arc welding
Last Answer : In which of the following welding methods, the molten metal is poured for joining the metals ? (a) Gas welding (b) Thermit welding (c) TIG welding (d) Arc welding
Description : Out of HCI and CH3COOH, which one is a weak acid and why? Describe an activity to support your answer. -Chemistry
Last Answer : Acetic acid ( CH3COOH) is a weaker acid because it does not dissociate completely into its ions in aqueous solution. Activity: Add zinc metal in HCI and CH3COOH respectively. The hydrogen gas will be evolved ... and light red in CH3COOH which shows HCI is a strong acid and CH3COOH is a weak acid.
Description : What is weak acid ? What is weak acid ?
Last Answer : Acids that are not completely dissolved in water but are partially decomposed, that is, all the acid molecules that do not produce hydrogen ions ( H +) are called weak acids.
Description : The bats can fly in the dark because – (1) They can see the objects in darkness (2) They have weak legs and are likely to be attacked by predators (3) They generate flashes of light (4) They generate ultrasonic sound waves
Last Answer : (3) They generate flashes of light
Description : Bonds formed by the sharing of an electron pair between two atoms are known as - (1) Covalent bonds (2) Ionic bonds (3) Weak bonds (4) None of the above
Last Answer : (1) Covalent bonds Explanation: Bonds which are formed by the sharing of an electron pair between two atoms are known as covalent bonds.
Description : How much is the percentage ionization of an electrolyte to classified is as 'weak electrolyte'?
Last Answer : Ans:
Description : Predict what will happen if intermolecular forces between the molecules are very weak
Last Answer : Ans. When intermolecular forces are very weak , molecules do not cling together t o make liquid and solid.
Description : Alcohols acts as weak bases. Explain.
Last Answer : The oxygen atom of the hydroxyl group has two lone pairs of electrons. Therefore alcohols accept a proton from strong mineral acid to form oxonium ions. Hence act as weak bases.
Description : Which of the following statements is correct about aniline? (a) is weak acid. (b) diazotizes to benzenediazonium chloride when treated with ice-cold nitrous acid. (c) can be nitrated with ... p-nitroaniline. (d) gives an intense green color with a suspension of bleaching powder in water
Last Answer : diazotizes to benzenediazonium chloride when treated with ice-cold nitrous acid.
Description : Which of the following statements is false about aniline? (a) It is a primary aromatic amine. (b) It is a weak base which forms salts with acids. (c) It liberates nitrogen on treatment with ice-cold nitrous acid. (d) It can be prepared by the reduction of nitrobenzene with tin and HCl
Last Answer : It liberates nitrogen on treatment with ice-cold nitrous acid
Description : Amines are generally classified as (a) Weak acids (b) Strong acids (c) Weak bases (d) Strong bases
Last Answer : Weak bases
Description : Which of the following is not a property of thiols (RSH)? (a) They are all solids (b) They can be oxidized to disulfides (c) They have foul odors (d) They are weak acids
Last Answer : They are all solids
Description : Which brief statement most accurately describes why alkenes react the way they do? (a) C=C double bonds are weak. (b) A π bond is lost but a stronger σ bond is gained. (c) C=C double bonds are unstable. (d) C=C π bonds are attacked by nucleophiles.
Last Answer : A π bond is lost but a stronger σ bond is gained.
Description : The noble gases have low boiling points because: w) their ionization potentials are very low x) only weak Van der Waals forces hold the atoms together y) they are produced by the fractional distillation of liquid air z) they have eight electrons in the outer shell
Last Answer : ANSWER: X -- ONLY WEAK VAN DER WAALS FORCES HOLD THE ATOMS TOGETHER