Classification of Modern Periodic Table

Q.

How can we find in which period and group in periodic table a element exist. Explain whole method thoroughly?

Q.

how Fe3O4 is formed, oxygen doesn't have the valency 3 then how it's Fe3O4

Q.

Why is hydrogen placed in group one?

Q.

A metal sulphate has the formula MSO4. A cloride of the same metal will have the formula

(A)M2cl3

(B)M2cl

(C)Mcl2

(D)Mcl

Q.

The maximum number of electrons in d subshell is equal to:

1. 2

2. 6

3. 10

4. 14

Q.

Define atomic radius of an element. How does it vary along the period and group? [3 MARKS]

Q. What is meant by a group in the periodic table?

Q.

Why is Mercury called quicksilver?

Q.

How does electronic configuration of atoms change in a period with increase in atomic number? [2 MARKS]

Q.

Why is the chemical formula of iron oxide Fe₃O₄ when the valency of iron is 2, 3 and that of oxygen is 2

Q. How many shells in calcium atom are filled with electrons?

1. Two
2. Three
3. Five
4. Four

Q. The following table represents the first three periods of the modern periodic table. Study the table and answer the questions that follow:
(i) Write the formula of the sulphate of the element with atomic number 13.
(ii) What type of bonding will be present in the oxide of the element with atomic number 1?
(iii) Which feature of the atomic structure accounts for the similarities in the chemical properties of the elements in group VIIA of the periodic table?
(iv) Name the element which has the highest ionization potential.
(v) How many electrons are present in the valence shell of the element with atomic number 18?

Figure

(vi) What is the name given to the energy released, when an atom in its isolated gaseous state accepts an electron to form an anion?
(vii) What is the electronic configuration of the element in the third period which gains one electron to become an anion?
(viii) Fill in the blanks:
The atomic size ________ as we move from left to right across the period, because the ________ increases, but the ________ remains the same.

Q.

How and why does the atomic size vary as you go:
1. From left to right across a period?
2. Down a group?
[3 MARKS]

Q. Observe the following diagram and write the answer of the following question.

1. Write the atomic numbers of the first two elements in the second group.
2. Write the number of valence electrons of the elements in the halogen group.
3. Draw the diagram of the electronic configuration of the magnesium atom.
4. After completing a period, what change does take place in the electronic configuration of the next element?
5. Write the names of any two elements from the diagram which do not take part in a chemical reaction.

Q.

An element 'M' has atomic number 11. [5 MARKS]
1. Write its electronic configuration.
2. State the group to which 'M' belongs.
3. Is 'M' a metal or a non-metal?
4. Write the formula of its chloride.
5. Name at least four elements present in this group.

Q.

Name the element and the chemical symbol of the alkaline earth metal with the smallest atomic number. What is the number of valence electrons present in it?

Q.

Consider the section of the Periodic Table given below:

Note: In this table:

B does not represent boron. C does not represent carbon. F does not represent fluorine. H does not represent hydrogen. K does not represent potassium.

You must see the position of the element in the Periodic Table.

Some elements are given in their own symbol and position in the Periodic Table while others are shown with a letter. With reference to the table:

Write the formula of the compound between B and H.

1. B₂H

2. B₂H₂

3. BH

4. BH₂

Q.

Write scientific reason : Atomic radius goes on decreasing while going from left to right in a period

Q.

The position of three elements A, B and C in the periodic table are shown below: [5 MARKS]

(a) State whether A is a metal or non-metals.

(b) Will C be larger or smaller in size than B?
(C) State whether C is more reactive or less reactive than A.
(d) Which type of ion, cation, or anion will be formed by element A?
(e) Give two examples of group 17.

Q.

Element ‘A’ is used for the manufacture of match sticks. Predict the position of A in the modern periodic table.

1. V-A group and third period

2. IV-A group and third period

3. V-A group and fourth period

4. IV-A group and fourth period

Q.

How many elements are there in sixth period in modern periodic table.

Q. ______ is the only noble gas which does not have 8 electrons in its outermost orbit.

1. Helium
2. Argon
3. Neon
4. Krypton

Q. Which of the following is true about Noble gases?

1. They are not reactive
2. They are non-metallic
3. They exist in the atomic state
4. All of the above

Q. The atomic number of an element is 20. Write its electronic configuration. State whether this element is a metal or a non-metal. What is its valency? Write the name and formula of the compound whch this element forms with chlorine.

Q. Three elements A, B and C have atomic number 7, 8 and 9 respectively.What would be their positions in the modern periodic table mention group and period.Arrange A, B and C in the decreasing order of their size.Which one of the three elements is most reactive and why?

Q. Most nonmetallic elements are present on the left side of the periodic table.

1. True
2. False

Q. Which of the following are true for modern periodic table?

1. Allotropes take the same place as the element.
2. Metals, non metals and metalloids are placed in an orderly manner.
3. Elements are placed in increasing order of atomic number.
4. Isotopes take the same place as the element.

Q.

An element Y is in second period and group 16 of the periodic table :

(i) Is it a metal or non-metal?

(ii) What is the number of valence electrons in its atom?

(iii) What is its valency?

(iv) What is the name of the element?

(v) What will be the formula of the compound formed by Y with Sodium?

Q.

How will the tendency to gain electrons change as we go from left to right across a period? Why? [2 MARKS]

Q. Which of the following is the correct order of melting points of alkanes?

1. $C_5{H}_{12}<C_6{H}_{14}<C_7{H}_{16}<C_8{H}_{18}$
2. $C_8{H}_{18}<C_7{H}_{16}<C_6{H}_{14}<C_5{H}_{12}$
3. $C_8{H}_{18}<C_6{H}_{14}<C_7{H}_{16}<C_5{H}_{12}$
4. $C_5{H}_{12}<C_6{H}_{14}<C_8{H}_{18}<C_7{H}_{16}$