Groups in Modern Periodic Table

Q.

Draw electron dot structures for each of the following:
(a) MgCl₂
(b) CaO
(c) NaCl

Q.

What are the horizontal rows in the modern periodic table called?

Q. Write scientific reason: Elements belonging to the same group have the same valency.

Q.

How many valence electrons would be found in Anatomy with the atomic number of 51?

Q.

Write the symbol and valency of nitride.

Q.

why lanthanides and actinides are place separately in periodic table

Q.

Write the symbol and valency of peroxide.

Q. The chemistry of lithium is very similar to that of magnesium even though they are placed in different groups, because:

1. both have nearly the same size.
2. both are found together in nature.
3. both have similar electronic configuration.
4. the ratio of their charge to size is nearly the same.

Q. what is representative elements and which of the following set of atomic no represents representative elements (1)5, 13, 30, 53 (2)11, 33, 58, 84 (3)5, 17, 31, 54 (4)9, 31, 53, 8

Q.

A non-metal A is an important constituent of our food and forms two oxides B and C. Oxide B is toxic whereas C causes global warming (a) Identify A, B and C (b) To which Group of Periodic Table does A belong?

Q. Question 2
Element X forms a chloride with the formula ${\text{XCl}}_2$, which is a solid with a high melting point. X would most likely be in the same group of the periodic table as:
1. Na
2. Mg
3. Al
4. Si

Q. A non-metal X is an important constituent of our food. It forms two oxides Y and Z. Y is toxic and causes suffocation and even death while Z is responsible for global warming. Identify X, Y and Z.

1. $X=C,Y=CO,Z=C{O}_2$
2. $X=S,Y=S{O}_2,Z=S{O}_3$
3. $X=P,Y=P_2{O}_3,Z=P_2{O}_5$
4. $X=O,Y=O_2,Z=O_3$

Q.

An element X from group 2 of the periodic table reacts with an element Y from group 17 to form a compound.

(a) What is the nature of the compound formed?

(b) State whether the compound formed will conduct electricity or not.

(c) Give the formula of the compound formed.

(d) What is the valency of element X?

(e) How many electrons are there in the outermost shell of an atom of element Y?

Q.

A non-metal A which is the largest constituent of air, when heated with H₂ in 1:3 ratio in the presence of a catalyst (Fe) gives a gas B. On heating with O₂ it gives an oxide C. If this oxide is passed into water in the presence of air, it gives an acid D which acts as a strong oxidising agent. (a) Identify A, B, C and D (b) To which group of periodic table does this non-metal belong?

Q.

What property of an element determines its chemical behaviour?

1. Size of an element

2. Valency of an element

3. Molar mass of the element

4. None of these

Q. why do the halogens show high tendency to form compounds with alkali metals and earth metals?

Q.

The atomic numbers of three elements A, B and C are given below :

Element Atomic number

A 5

B 7

C 10

(i) Which element belongs to group 18? (ii) Which element belongs to group 15?

(iii) Which element belongs to group 13? (iv) To which, period/periods do these elements belong?

Q.

An element X combines with oxygen to form an oxide XO. This oxide is electrically conducting.

(a) How many electrons would be there in the outermost shell of the element X?

(b) To which group of the periodic table does the element X belong?

(c) Write the formula of the compound formed when X reacts with chlorine.

Q.

Which of the following statement about modern periodic table is correct?

1. It has 18 horizontal rows known as periods.

2. It has 18 vertical columns known as groups.

3. It has 7 vertical columns known as periods.

4. It has 7 horizontal rows known as groups.

Q.

(a) An element X has mass number 40 and contains 21 neutrons in its atom. To which group of the periodic table does it belong?

(b) The element X forms a compound $X_2$Y. Suggest an element that Y might be and give reasons for your choice.

Q.

Example for an inert gas is ---------

Q.

An element A from group 14 of the periodic table combines with an element B from group 16.

(i) What type of chemical bond is formed?

(ii) Give the formula of the compound formed.

Q.

The atomic numbers of the three elements X, Y and Z are 2, 6 and 10 respectively.

(i) Which two elements belong to the same group?

(ii) Which two elements belong to the same period?

Give reasons for your choice.

Q.

d-block elements are also called as__________?

Q. All the elements in a group have:

1. same mass number
2. same number of isotopes
3. same number of shells
4. same number of valence electrons

Q.

The electronic configuration of the atom of an element X is 2, 8, 4. In the modern periodic table, the element X is placed in :

$\left(a\right)2^{nd}group$ $\left(b\right)4^{th}group$ $\left(c\right){14}^{th}group$ $\left(d\right)8^{th}group$

Q.

An element X belongs to group 2 and another element Y belongs to group 15 of the periodic table :

(a) What is the number of valence electrons in X? (b) What is the valency of X?

(b) What is the number of valence electrons in Y? (d) What is the valency of Y?

Explain how you have arrived at your answers.

Q.

A metal X is in the first group of the periodic table. What will be the formula of its oxide?

Q.

Consider the following elements :

${}_{20}Ca{,}_{8}O,{}_{18}Ar,{}_{16}S,{}_{4}Be,{}_{2}He$

Which of the above elements would you expect to be :

(i) very stable? (ii) in group 2 of the periodic table?

(iii) in group 16 of the periodic table ?

Q.

Element X has 12 protons in its nucleus. To which group in the periodic table would it belong?

1. IVA (14)

2. IIA (2)

3. IIIA (13)

4. VIA (16)