Problem 5 - Biology: Science for Life with Physiology

Question

Electrons _______ A. are negatively charged; B. along with neutrons comprise the nucleus; C. are attracted to the negatively charged nucleus; D. located closest to the nucleus have the most energy; E. all of the above are true.

Step-by-Step Solution

Answer

The correct answer is A: Electrons are negatively charged.

Step 1: Understanding the Options

We are asked to determine which statement about electrons is true. Let's analyze what is known about electrons to evaluate each statement.

Step 2: Evaluating Option A

Option A states that electrons are negatively charged. This is true, as electrons have a fundamental negative charge of  e^{1-}. Therefore, option A is true.

Step 3: Evaluating Option B

Option B states that electrons, along with neutrons, comprise the nucleus. This is false because the nucleus is made up of protons and neutrons, not electrons.

Step 4: Evaluating Option C

Option C claims that electrons are attracted to the negatively charged nucleus. This statement is false; electrons are actually attracted to the positively charged nucleus due to the opposite charges.

Step 5: Evaluating Option D

Option D states that electrons located closest to the nucleus have the most energy. This is incorrect because electrons closest to the nucleus are in lower energy levels compared to those further away.

Step 6: Evaluating Option E

Option E declares that all of the above are true. Since we found that only option A is accurate, option E cannot be true.

Step 7: Conclusion

After evaluating each option, only option A is true: electrons are negatively charged.

Key Concepts

Atomic Structure

Atomic structure is a fundamental concept in understanding matter and its interactions. It describes how atoms are organized and how these arrangements govern the properties of elements. At the core of atomic structure is an atom's nucleus, a dense region at the center. This nucleus is comprised primarily of protons, which carry a positive charge, and neutrons, which are neutral. Surrounding the nucleus are electrons.

• Electrons are found in regions called electron clouds or orbitals.
• These orbitals are not fixed paths but probability zones where electrons are likely to be found.
• The overall structure determines how atoms interact with each other.

Understanding atomic structure helps you grasp why elements behave the way they do in chemical reactions.

Negative Charge

The concept of negative charge is crucial in chemistry and physics. Electrons are subatomic particles that possess a negative charge. This charge is crucial as it influences how electrons interact with other particles and fields.

• Electrons each carry a charge of \( -1.6 \times 10^{-19} \) coulombs.
• They play a crucial role in electricity, moving through conductive materials to create electric currents.
• The negative charge of electrons is what allows them to bond with positively charged protons.

Their negativity is a key property that creates the attraction between electrons and the positively charged nucleus, fundamentally affecting the atom's stability and reactivity.

Energy Levels

Electrons in an atom are organized into energy levels, which are also known as shells or orbitals. These levels are determined by the quantum mechanical principle, where electrons are arranged according to increasing energy.

• Electrons closer to the nucleus occupy lower energy levels.
• Higher energy levels are located further away and are filled as the atom gains more electrons.
• These levels affect how elements react chemically and influence the atom's stability.

The energy required to remove an electron from an atom is called ionization energy and increases as electrons are closer to the nucleus due to stronger attractions. Understanding energy levels is vital in analyzing and predicting chemical behavior.

Nucleus Composition

The nucleus is the heart of the atom and is key to its stability and identity. Comprised of protons and neutrons, it forms the dense core while electrons orbit around it. Together, protons and neutrons are called nucleons, and their interaction is governed by strong nuclear forces.

• Protons give the nucleus its positive charge and determine the atom's identity.
• Neutrons contribute mass and add stability, holding protons together in the nucleus.
• The number of protons, known as the atomic number, defines the element.

By understanding nucleus composition, one can explain phenomena like radioactivity and atomic energy, crucial to advanced scientific study and applications. The nucleus profoundly influences how atoms interact and bind with others, determining the variety of compounds formed in nature.