Chapter 1, Problem 1.76EP

(a)

Interpretation Introduction

Interpretation:

The chemical notation $Hf$ is the chemical symbol for an element or a chemical formula of a compound has to be indicated and total number of atoms present in one formula unit of the substance has to be indicated.

Concept Introduction:

The composition of a chemical compound can be presented in a very precise was with the use of chemical formula.  Chemical formula uses chemical symbols of the elements that is present in the compound and numerical subscripts that represent how many number of atoms of each element is present in the compound.

Answer to Problem 1.76EP

$Hf$ is chemical formula for an element and total number of atoms present is 1.

Explanation of Solution

Given chemical notation is $Hf$.  As there are only one atom present in the given chemical notation, it is a chemical formula of an element.

The total number of atoms present in the chemical formula is found by summing up the subscript present in the chemical formula.

  $\begin{array}{l}TotalNo.ofatoms=1Hfatom\\ =1atom\end{array}$

Therefore, there is one atom in the given chemical formula.

(b)

Interpretation Introduction

Interpretation:

The chemical notation $HF$ is the chemical symbol for an element or a chemical formula of a compound has to be indicated and total number of atoms present in one formula unit of the substance has to be indicated.

Concept Introduction:

The composition of a chemical compound can be presented in a very precise was with the use of chemical formula.  Chemical formula uses chemical symbols of the elements that is present in the compound and numerical subscripts that represent how many number of atoms of each element is present in the compound.

Answer to Problem 1.76EP

$HF$ is chemical formula for a compound and total number of atoms present is 2.

Explanation of Solution

Given chemical notation is $HF$.  As there are more than two elements present in the given chemical notation, it is a chemical formula of a compound.

The total number of atoms present in the chemical formula is found by summing up the subscript present in the chemical formula.

  $\begin{array}{l}TotalNo.ofatoms=1Hatom+1Fatom\\ =2atoms\end{array}$

Therefore, there are two atoms in the given chemical formula.

(c)

Interpretation Introduction

Interpretation:

The chemical notation $CoC{l}_2$ is the chemical symbol for an element or a chemical formula of a compound has to be indicated and total number of atoms present in one formula unit of the substance has to be indicated.

Concept Introduction:

The composition of a chemical compound can be presented in a very precise was with the use of chemical formula.  Chemical formula uses chemical symbols of the elements that is present in the compound and numerical subscripts that represent how many number of atoms of each element is present in the compound.

Answer to Problem 1.76EP

$CoC{l}_2$ is chemical formula for a compound and total number of atoms present is 3.

Explanation of Solution

Given chemical notation is $CoC{l}_2$.  As there are more than one element present in the given chemical notation, it is a chemical formula of a compound.

The total number of atoms present in the chemical formula is found by summing up the subscript present in the chemical formula.

  $\begin{array}{l}TotalNo.ofatoms=1Co\text{}atom+2Clatoms\\ =3atoms\end{array}$

Therefore, there are three atoms in the given chemical formula.

(c)

Interpretation Introduction

Interpretation:

The chemical notation $COC{l}_2$ is the chemical symbol for an element or a chemical formula of a compound has to be indicated and total number of atoms present in one formula unit of the substance has to be indicated.

Concept Introduction:

The composition of a chemical compound can be presented in a very precise was with the use of chemical formula.  Chemical formula uses chemical symbols of the elements that is present in the compound and numerical subscripts that represent how many number of atoms of each element is present in the compound.

Answer to Problem 1.76EP

$COC{l}_2$ is chemical formula for a compound and total number of atoms present is 4.

Explanation of Solution

Given chemical notation is $COC{l}_2$.  As there are more than one element present in the given chemical notation, it is a chemical formula of a compound.

The total number of atoms present in the chemical formula is found by summing up the subscript present in the chemical formula.

  $\begin{array}{l}TotalNo.ofatoms=1C\text{}atom+1Oatom+2Clatoms\\ =4atoms\end{array}$

Therefore, there are four atoms in the given chemical formula.