1. In the periodic table, the element with atomic number 16 will be placed in the group ___________.
A. Third
B. Fourth
C. Fifth
D. Sixth
ANSWER:D.Sixth
SOLUTION : Sixth
2. The group number, number of valence electrons, and valency of an element with the atomic number 15, respectively , are _________.
A. 16, 5 and 2
B. 15, 5 and 3
C. 16, 6 and 3
D. 15, 6 and 2
ANSWER:B.15, 5 and 3
SOLUTION:The group number, number of valence electrons, and valency of an element with the atomic number 15 are 15, 5, and 3, respectively. This element is phosphorus.
3. Which of the following element will become stable after losing and electron?
A. Helium
B. Iodine
C. Sodium
D. Oxygen
ANSWER : C.Sodium
SOLUTION: SODIUM is the element which would become stable by losing an electron. It becomes an ION in its IONIZATION. As SODIUM loses 1 electron, it is left with (11) protons & (10) electrons. Hydrogen & lithium are also in Group -1 elements with SODIUM.
4. Contain 9 Protons, 10 electrons and 11 neutrons . It is __________.
A. A neutral atom
B. An Isotope
C. A cation
D. An anion
ANSWER:D.An anion
SOLUTION:A species with 9 protons, 10 electrons, and 11 neutrons is an anion with an atomic number of 9 and an electronic configuration of 2,7. This means that the species can easily gain an electron to complete its octet, resulting in 10 electrons and an electron configuration of 2,8. Since the species has one extra electron compared to the number of protons, it has a unit negative charge.
5. Which pair of elements belongs to same group?
A. Elements with atomic no 17 and 38
B. Elements with atomic no 20 and 40
C. Elements with atomic no 17 and 53
D. Elements with atomic no 11 and 33
ANSWER:C.Elements with atomic no 17 and 53
SOLUTION:In conclusion, the correct pair of elements that belongs to the same group is “Elements with atomic no. 17 and 53” (Chlorine and Iodine).
6. What is the total number of electrons in the Chlorine molecule?
A. 17
B. 34
C. 18
D. 16
ANSWER:A.17
SOLUTION:Atomic number of Cl is 17. So, its neutral atom contains 17 electrons as it’s nucleus contains 17 protons. Cl- anion more one electron. That means, Cl- contains total 18 electrons.
7. Which among the following is not a property of ionic bond?
A. Losing of electrons
B. Gain of electrons
C. Sharing of electrons
D. Transfer of electrons
ANSWER:C.Sharing of electrons
SOLUTION :
The property from the options which does not describe an ionic bond is: Sharing of electrons.
8. The reason of bonding in ionic compounds is ________.
A. Sharing of electrons
B. Repulsion force
C. Attraction force
D. None of these
ANSWER: C.Attraction force
SOLUTION: Attraction force
9. A molecule of _______ Contains a triple bond.
A. Sulphur
B. Nitrogen
C. Carbon
D. Oxygen
ANSWER:B.Nitrogen
SOLUTION: A nitrogen molecule (N2) contains a triple covalent bond between two nitrogen atoms.
10. Which of the following is not a typical property of an ionic compound?
A. High melting point
B. Conducts electricity in the molten and in the aqueous solution state
C. They are soluble in water
D. They are insoluble in water
ANSWER: D.They are insoluble in water
SOLUTION:
Insolubility in water is not a typical property of an ionic compound. In fact, ionic compounds are usually soluble in water.