Problem 3 - Campbell Biology Concepts & Connections

Question

Changing the ______ would change it into an atom of a different element. a. number of electrons surrounding the nucleus of an atom b. number of protons in the nucleus of an atom c. electrical charge of an atom d. number of neutrons in the nucleus of an atom

Step-by-Step Solution

Answer

b. number of protons in the nucleus of an atom

Step 1: Identify the core characteristic of an element

To determine which option changes the identity of an element, understand that elements are defined by the number of protons in their nucleus. An element is uniquely identified by its atomic number, which is the number of protons.

Step 2: Analyze each option

Review each answer choice to see which one affects the number of protons. - Option a: Changing the number of electrons does not change the element, it only ionizes it. - Option b: Changing the number of protons changes the atomic number, thus changing the element. - Option c: Changing the electrical charge influences ionization, not the element itself. - Option d: Changing the number of neutrons creates isotopes, not a different element.

Step 3: Determine the correct answer

Only changing the number of protons in the nucleus of an atom changes it into an atom of a different element. Protons determine the element's identity.

Key Concepts

Protons

Protons are subatomic particles found in the nucleus of an atom. They have a positive electrical charge. Each proton carries a charge of +1. Protons help determine the identity of an element. The number of protons in an atom's nucleus is called the atomic number.
For example, hydrogen has one proton.
Having more or fewer protons changes the element itself.

• Protons are tightly bound together with neutrons in the atomic nucleus.
• The strong force binds protons and neutrons together.
• Having more protons means a greater positive charge in the nucleus.

This positive charge results in an electric force that attracts negatively charged electrons. This attraction stabilizes the atom. The number of protons distinguishes one element from another.

Atomic Number

The atomic number of an element is the number of protons in the nucleus of its atoms. Each element has a unique atomic number. For example, carbon has an atomic number of 6, meaning every carbon atom has 6 protons.

• The periodic table is organized by atomic numbers.
• Elements with consecutive atomic numbers are chemically different from each other.
• Changing the atomic number changes the element.

To illustrate, if you add one proton to a carbon atom, it becomes nitrogen with an atomic number of 7.
The atomic number is central to understanding the behavior and characteristics of elements.

Elements

Elements are pure substances consisting of only one type of atom. They are defined by the number of protons in their nuclei. Elements are the basic building blocks of matter. There are a little over 100 known elements, ranging from simple ones like hydrogen to complex ones like uranium.

• Elements cannot be broken down into simpler substances by chemical reactions.
• They are organized in the periodic table based on their atomic numbers.
• Each element has unique properties due to its atomic structure.

These properties include atomic mass, reactivity, and bonding behavior. For instance, oxygen is highly reactive and bonds easily with hydrogen to form water. Understanding elements and their atomic structure is fundamental in chemistry and physics.