Chapter 9, Problem 1STP

Summary Introduction

Introduction:

Elements combine to form compounds. Compounds have unique characteristics. They are formed from specific combination of elements in a fixed ratio. The force that holds the atoms together in a molecule of a compound is called chemical bond. When atoms share electrons to form a bond, it is called covalent bond. When atoms gain or lose electrons to form a bond, it is called ionic bond. Carbon forms covalent bond with other atoms.

Answer to Problem 1STP

Correct answer :

The correct answer is option C. CF₄

Explanation of Solution

Explanation/justification for the correct answer:

Option C. CF₄−Carbon has four electrons in its outermost shell and fluorine has seven electrons in its outermost shell. Onecarbon atom can share electrons with four different fluorine atoms to complete its outer energy level. It forms four covalent bonds, one with each fluorine atom.Hence one carbon atom can combine with four fluorine atoms to form a compound CF₄.

  

Hence this is the correct option.

Explanation for incorrect answer:

Option A. CF₂−One carbon atom can share electrons with four different fluorine atoms to complete its outer energy level. It forms four covalent bonds, one with each fluorine atom. Hence one carbon atom can combine with four fluorine atoms to form a compound CF₄. Carbon cannot satisfy outer energy level with only two fluorine atoms.

Hence this is not the correct option.

Option B. CF₃- One carbon atom can share electrons with four different fluorine atoms to complete its outer energy level. It forms four covalent bonds, one with each fluorine atom. Hence one carbon atom can combine with four fluorine atoms to form a compound CF₄. Carbon cannot satisfy outer energy level with only three fluorine atoms.

Hence this is not the correct option.

Option D. CF₅- One carbon atom can share electrons with four different fluorine atoms to complete its outer energy level. It forms four covalent bonds, one with each fluorine atom. Hence one carbon atom can combine with four fluorine atoms to form a compound CF₄. Carbon cannot combine with five fluorine atoms.

Hence this is not the correct option.