Two shells, both of which are completely filled with electrons?
Answer: Ne (Neon)The electronic configuration 2, 8, 2?
Answer: Mg (Magnesium)A total of three shells, with four electrons in its valence shell?
Answer: Si (Silicon) (14): 2, 8, 4A total of two shells, with three electrons in its valence shell?
Answer: B (Boron) (5): 2, 3
Which of the following statements is not a correct statement about the trends when going from left to right across the periods of periodic Table. The elements become less metallic in nature. The number of valence electrons increases. The atoms lose their electrons more easily. The oxides become more acidic.
Answer: (c) The atoms lose their electrons more easily
Element X forms a chloride with the formula XCl2, which is a solid with a high melting point. X would most likely be in the same group of the Periodic Table as Na Mg Al Si
Answer: (b) Mg
What property do all elements in the same column of the Periodic Table as boron have in common?
Answer: Boron is metalloid while all other elements in the same column of the Periodic Table are metals, thus metallic character is common in the same column of the periodic table as boron have.What property do all elements in the same column of the Periodic Table as fluorine have in common?
Answer: All elements belong to same column as fluorine, are non-metals and are highly electronegative in character. All of them have valence electrons equal to seven, and thus can accept one electron to complete their octet.An atom has electronic configuration 2, 8, 7. What is the atomic number of this element?
Anwer: 17To which of the following elements would it be chemically similar? (Atomic numbers are given in parentheses.) N(7) F(9) P(15) Ar(18)
Anwer: F (9) Fluorine (As fluorine has valence electron equal to seven)
| Group 16 | Group 17 |
|---|---|
| A | |
| B | C |
State whether A is a metal or non-metal.
Answer: Non-metalState whether C is more reactive or less reactive than A.
Answer: Less reactive than AWill C be larger or smaller in size than B?
Answer: SmallerWhich type of ion, cation or anion, will be formed by element A?
Answer: Anion
Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the Periodic Table. Write the electronic configuration of these two elements. Which of these will be more electronegative? Why?
Answer: Nitrogen (7): 2, 5Phosphorus (15): 2, 8, 5Since, electronegativity decreases with moving from top to bottom in a group, thus Nitrogen will be more electronegative.How does the electronic configuration of an atom relate to its position in the Modern Periodic Table?
Answer: Electronic configuration of an element gives the information of valence electrons and number of shell present in the element. We get the information of group number after knowing valence electrons. Number of shells present in an element is equal to period number. Thus, by knowing electronic configuration we know the group number and period number of an element, which is the position of element in periodic table.
In the Modern Periodic Table, calcium (atomic number 20) is surrounded by elements with atomic numbers 12, 19, 21 and 38. Which of these have physical and chemical properties resembling calcium?
Answer: Elements with atomic numbers 12 and 38 have the similar chemical and physical properties of calcium.Compare and contrast the arrangement of elements in Mendeléev’s Periodic Table and the Modern Periodic Table.
Answer: Comparison of Mendeleev’s Periodic Table and Modern Periodic Table
| Mendeleev's Periodic Table | Modern Periodic Table |
|---|---|
| Elements were arranged in increasing order of atomic masses. | Elements are arranged in increasing order of atomic numbers. |
| There are 8 groups. | There are 18 groups. |
| Each group is divided into sub groups a and b. | Groups are not divided into sub groups. |
| Group for noble gases was not present, as noble gases were not discovered at that time. | A separate group, i.e. group 18 is present for noble gases. |
| There was no place for isotopes. | This problem was rectified, as slots are determined on the basis of atomic number. |
Oxygen Calcium Cobalt Potassium
Answer: (b) Calcium
According to Mendeleev's Periodic Law, the elements were arranged in the periodic table in the order of Increasing atomic number Decreasing atomic number Increasing atomic masses Decreasing atomic masses
Answer: (c) Increasing atomic masses
In Mendeleev’s Periodic Table, gaps were left for the elements to be discovered later. Which of the following elements found a place in the periodic table later Germanium Chlorine Oxygen Silicon
Answer: (a) Germanium
Which of the following statement (s) about the Modern Periodic Table are incorrect The elements in the Modern Periodic Table are arranged on the basis of their decreasing atomic number The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic masses Isotopes are placed in adjoining group (s) in the Periodic Table The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic number
(i) only (i), (ii) and (iii) (i), (ii) and (iv) (iv) only
Answer: (b) (i), (ii) and (iii)
Which of the given elements A, B, C, D and E with atomic number 2, 3, 7, 10 and 30 respectively belong to the same period? A, B, C B, C, D A, D, E B, D, E
Answer: (b) B, C, D
The elements A, B, C, D and E have atomic number 9, 11, 17, 12 and 13 respectively. Which pair of elements belongs to the same group? A and B B and D A and C D and E
Answer: (a) A and B
Where would you locate the element with electronic configuration 2,8 in the Modern Periodic Table? Group 8 Group 2 Group 18 Group 10
Answer: (c) Group 18
An element which is an essential constituent of all organic compounds belongs to Group 1 Group 14 Group 15 Group 16
Answer: (b) Group 14
Which of the following statements about the Modern Periodic Table is correct: It has 18 horizontal rows known as Periods It has 7 vertical columns known as Periods It has 18 vertical columns known as Groups It has 7 horizontal rows known as Groups
Answer: (c) It has 18 vertical columns known as GroupsWhich of the following is the outermost shell for elements of period 2? K shell L shell M shell N shell
Answer: (b) L shell
Which one of the following elements exhibit maximum number of valence electrons? Na Al Si P
Answer: (d) P
Which of the following gives the correct increasing order of the atomic radii of O, F and N? O, F, N N, F, O O, N, F F, O, N
Answer: (d) F, O, N
Which among the following elements has the largest atomic radii? Na Mg K Ca
Answer: (c) K
Which of the following elements would lose an electron easily? Mg Na K Ca
Answer: (c) K
Which of the following elements does not lose an electron easily? Na F Mg Al
Answer: (b) F
Which of the following are the characteristics of isotopes of an element? Isotopes of an element have same atomic masses Isotopes of an element have same atomic number Isotopes of an element show same physical properties Isotopes of an element show same chemical properties
(i), (iii) and (iv) (ii), (iii) and (iv) (ii) and (iii) (ii) and (iv)
Answer: (b) (ii), (iii) and (iv)
Arrange the following elements in the order of their decreasing metallic character: Na, Si, Cl, Mg, Al Cl > Si >Al > Mg > Na Na >Mg >Al >Si > Cl Na > Al > Mg > Cl > Si Al > Na> Si > Ca > Mg
Answer: (b) Na > Mg > Al > Si > Cl
Arrange the following elements in the order of their increasing nonmetallic character: Li, O, C, Be, F F < O < C < Be < Li Li < Be < C < O< F F < O < C < Be < Li F < O < Be < C < Li
Answer: (c) F < O < C < Be < LiWhat type of oxide would Eka– aluminium form? EO3 E3O2 E2O3 EO
Answer: (c) E2O3
Three elements B, Si and Ge are Metals Non-metals Metalloids Metal, non-metal and metalloid respectively
Answer: (c) Metalloids
Which of the following elements will form an acidic oxide? An element with atomic number 7 An element with atomic number 3 An element with atomic number 12 An element with atomic number 19
Answer: (a) An element with atomic number 7
Which one of the following depicts the correct representation of atomic radius(r) of an atom? (i) and (ii) (ii) and (iii) (iii) and (iv) (i) and (iv)
Answer: (b) (ii) and (iii)
Which one of the following does not increase while moving down the group of the periodic table? Atomic radius Metallic character Valence Number of shells in an element
Answer: (c) Valence
On moving from left to right in a period in the periodic table, the size of the atom. Increases Decreases does not change appreciably first decreases and then increases
Answer: (b) Decreases
Which of the following set of elements is written in order of their increasing metallic character? Be Mg Ca Na Li K Mg Al Si C O N
Answer: (a) Be Mg Ca
The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following categories does the element belong? Metal Metalloid Non-metal Left-hand side element
Answer: (b) Metalloid
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