Chapter 3, Problem 18A

(a)

Interpretation Introduction

Interpretation: Whether the given statement is true or false needs to be determined.

Concept Introduction: Theory is a group of connected ideas or concepts intended to describe something.  It involves question- “why” or “how anything/ somethings happens. It is based on inference. Rutherford’s model of atom concluded that the atom is mostly empty space. However, the atom contains a nucleus where the mass and positive charge of the atom are concentrated.

Answer to Problem 18A

The given statement is false.

Explanation of Solution

Rutherford theorized that almost all mass of an atom & all of its positive charge are crammed into very small region of space at center of an atom. Rutherford’s new model of the atom fits the experimental data. In Rutherford's experiment, alpha particles are allowed to pass through a thin sheet of gold. This experiment was basically to know whether an atom has small dense nucleus with electrons revolving around it. The result of this experiment showed that atom contains mostly empty space with scattered electrons. Based on scattering of alpha particles, Rutherford determined that atom might have positive charge at center which contains most of its mass.

According to this, Rutherford's bombardment experiments proposed that alpha particles were being deflected (or bounced) by a dense, positively-charged nucleus. So, the given statement is false.

(b)

Interpretation Introduction

Interpretation: Whether the given statement is true or false needs to be determined.

Concept Introduction: We all know, all matter is made of chemicals; the importance of chemistry is that it's the study of everything. Chemistry is all about how something interacts to affect the structure, composition, as well as knowing properties of substances.

Answer to Problem 18A

The given statement is false.

Explanation of Solution

Protons are defined as a positively charged $\left(+ve\right)$ sub-atomic particles/ units found in the nucleus of an atom. Number of Protons present in an atom is known as atomic number. Atomic number is represented by symbol Z. Atomic number of an atom is the identity number of an element and the mass numbers are the number of electrons. Neutrons are subatomic particles found in the nucleus of an atom which are neutral.

The proton & neutron have like, but not have identical, masses. Protons & neutrons are termed as nucleons as they are present in nucleus.

Mass of protons, $m_P=1.6726\times {10}^{-27}Kg$

Mass of neutrons, $m_N=1.6749\times {10}^{-27}Kg$

So, the given statement is False.

(c)

Interpretation Introduction

Interpretation: Whether the given statement is true or false needs to be determined.

Concept Introduction: Every matter is made of chemicals; the importance of chemistry is that it's the study of everything. Chemistry is all about how something interacts to affect the structure, composition, as well as knowing properties of substances.

Answer to Problem 18A

The given statement is true.

Explanation of Solution

Protons are defined as a positively charged $\left(+ve\right)$ sub-atomic particles/ units found in the nucleus of an atom. Number of Protons present in an atom is known as atomic number. Atomic number is represented by symbol Z. Atomic number of an atom is the identity number of an element and the mass numbers are the number of electrons. Neutrons are subatomic particles found in the nucleus of an atom which are neutral.

The proton & neutron have like, but not have identical, masses. Protons & neutrons are termed as nucleons as they are present in nucleus. Electrons have negative charge and protons have the positive charge. Both, contribute greatly to the chemical properties of atom. So, the given statement is true.