Chapter 2, Problem 1TY

____________________ make up the nucleus of an atom.

1. Protons and electrons
2. Protons and neutrons
3. Protons, neutrons, and electrons
4. Neutrons and electrons
5. Electrons

Summary Introduction

Introduction:

All organisms and things around us are made from matter and matter is composed of atoms and molecules. Atoms combine together to make molecules and hence atoms are the fundamental units of matter. Atoms are further made up of three subatomic particles known as electrons, protons and neutrons.

Answer to Problem 1TY

Option (b) protons and neutrons.

Explanation of Solution

Explanation/justification for the correct answer:

Option (b) protons and neutrons. The protons and neutrons are present in the nucleus and make up the atomic mass of the atom. The electrons move around in the orbitals surrounding the atom and do not form a part of the nucleus. So, the correct answer is option (b).

Explanation for incorrect answer:

Option (a) Protons and electrons. The electrons are present in the orbitals that surround the nucleus of the atom. They are not present in the nucleus. So, this is an incorrect option.

Option (c) protons, neutrons and electrons. The protons and neutrons make up the nucleus of the atom but the electrons do not. So, this is an incorrect answer.

Option (d) neutrons and electrons. The neutrons are present in the nucleus of an atom but electrons are not. So, this is an incorrect answer.

Option (e) electrons. Electrons are present in the orbitals of an atom and not in the nucleus. So, this is an incorrect answer.