Skip to content
GK24
General ScienceMediumAsked in: RRB Group D · 16 Sep 2022, Shift 2

Which element does NOT belong to group number 11 in the Modern Periodic Table?

  1. A.Ag
  2. B.Au
  3. C.Cu
  4. D.Hg

Correct answer

D. Hg

Explanation

The correct answer is D, Hg. Mercury (Hg) belongs to group 12, not group 11. Group 11 of the modern periodic table holds copper (Cu, atomic number 29), silver (Ag, 47) and gold (Au, 79). These three are called the coinage metals because coins were made from them; each has one electron in its outermost s orbital, which makes them soft and shiny, and silver and copper are the best conductors of electricity of all metals. Mercury sits right next to gold in period 6 but in group 12, together with zinc and cadmium, and it is the only metal that is liquid at room temperature. A is wrong because silver is a group 11 metal. B is wrong because gold is also in group 11. C is wrong because copper heads group 11. Exam tip: Group 11 = Cu, Ag, Au (coinage metals); Group 12 = Zn, Cd, Hg; the liquid metal mercury is never a coinage metal.

View all
Q2.General ScienceAsked in: CDS · CDS-I 2019, GKEasy

Which one of the following statements is correct?

  1. A.Urea is produced in liver.
  2. B.Urea is produced in blood.
  3. C.Urea is produced from digestion of starch.
  4. D.Urea is produced in lung and kidney.
Show answer
Correct answer: A. Urea is produced in liver.

Liver cells turn the toxic ammonia released from the breakdown of amino acids into urea through the ornithine cycle, also called the urea cycle.

Q3.General ScienceAsked in: CDS · CDS-I 2019, GKMedium

Which one of the following is the correct sequence of passage of light in a compound microscope?

  1. A.Condenser-Objective lens-Eyepiece-Body tube
  2. B.Objective lens-Condenser-Body tube-Eyepiece
  3. C.Condenser-Objective lens-Body tube-Eyepiece
  4. D.Eyepiece-Objective lens-Body tube-Mirror
Show answer
Correct answer: C. Condenser-Objective lens-Body tube-Eyepiece

Light passes through the condenser to the specimen, is picked up by the objective lens, travels up the body tube and reaches the eye through the eyepiece.

Q4.General ScienceAsked in: CDS · CDS-I 2019, GKEasy

Which one of the following statements regarding haemoglobin is correct?

  1. A.Haemoglobin present in RBC can carry only oxygen but not carbon dioxide.
  2. B.Haemoglobin of RBC can carry both oxygen and carbon dioxide.
  3. C.Haemoglobin of RBC can carry only carbon dioxide.
  4. D.Haemoglobin is only used for blood clotting and not for carrying gases.
Show answer
Correct answer: B. Haemoglobin of RBC can carry both oxygen and carbon dioxide.

It binds oxygen at its iron-containing haem groups and carries some carbon dioxide on its protein chains. Each haemoglobin molecule has four polypeptide chains and four haem groups, and each haem iron can hold one oxygen molecule, forming oxyhaemoglobin in the lungs.

Q5.General ScienceAsked in: CDS · CDS-I 2019, GKEasy

Which one of the following statements regarding histone proteins is correct?

  1. A.Histones are proteins that are present in mitochondrial membrane.
  2. B.Histones are proteins that are present in nucleus in association with DNA.
  3. C.Histones are proteins associated with lipids in the cytosol.
  4. D.Histones are proteins associated with carbohydrates in the cytosol.
Show answer
Correct answer: B. Histones are proteins that are present in nucleus in association with DNA.

They are the proteins around which DNA winds to form chromatin in the nucleus of eukaryotic cells. Histones are small basic proteins, rich in the positively charged amino acids lysine and arginine, which attract the negatively charged phosphate groups of DNA.