Question 1

Which of the following elements is located in Period 3, Group 17 of the modern periodic table?

Accepted Answer

Chlorine (Cl) has atomic number 17, with electron configuration ending in 3p⁵, placing it in Period 3 and Group 17 (halogens).

Question 2

The atomic number of an element is 12. Which block of the periodic table does this element belong to?

Accepted Answer

Magnesium (Mg) with atomic number 12 has electron configuration [Ne]3s², with the last electron filling the s-orbital, making it an s-block element.

Question 3

Which of the following statements about the periodic table is correct?

Accepted Answer

As we move down a group, new electron shells are added, increasing the distance from nucleus to outermost electrons, thereby increasing atomic radius.

Question 4

An element has 4 electrons in its outermost shell and is in Period 2. What is its atomic number?

Accepted Answer

Carbon (C) is in Period 2 with 4 valence electrons (2s²2p²) and has atomic number 6.

Question 5

Which of the following statements about transition metals in the periodic table is correct?

Accepted Answer

Transition metals are characterized by partially filled d-orbitals and are located in Groups 3-12 of the periodic table.

Question 6

The atomic number of an element is 12. Which period and group does this element belong to in the periodic table?

Accepted Answer

Atomic number 12 is Magnesium (Mg), which has electronic configuration 2,8,2, placing it in Period 3 and Group 2 (alkaline earth metals).

Question 7

Which of the following elements is located in Group 17 of the modern periodic table?

Accepted Answer

Chlorine belongs to Group 17 (halogens), which are non-metals with 7 valence electrons.

Question 8

Which property of elements generally increases as you move from left to right across a period in the periodic table?

Accepted Answer

Non-metallic character increases from left to right across a period because elements gain electrons more readily as nuclear charge increases.

Question 9

An element has 4 valence electrons and is located in Period 2 of the periodic table. Which element is this?

Accepted Answer

Carbon has electronic configuration 2,4 with 4 valence electrons in Period 2, and belongs to Group 14.

Question 10

Which of the following elements has the highest electronegativity value on the Pauling scale?

Accepted Answer

Fluorine has the highest electronegativity value (4.0) on the Pauling scale among all elements because it is the most non-metallic and smallest halogen in Group 17.

Question 11

Elements in Group 2 of the periodic table are known as alkaline earth metals. What is the valence electron configuration of these elements?

Accepted Answer

All Group 2 elements have 2 valence electrons in their outermost s-orbital (ns²), making them divalent and chemically similar.

Question 12

The atomic radius of elements generally decreases across a period from left to right. Which of the following pairs correctly represents this trend?

Accepted Answer

Atomic radius decreases left to right in a period because increasing nuclear charge pulls electrons closer; Na (186 pm) > Mg (160 pm) > Al (143 pm) follows this trend.

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Periodic Table — Practice Questions