The reactivity of an atom arises from
- A. the average distance of the outermost electron shell from the nucleus.
- B. the existence of unpaired electrons in the valence shell.
- C. the sum of the potential energies of all the electron shells.
- D. the potential energy of the valence shall.
Introduction:
An atom is the smallest possible particle of an element. It is the basic unit of any structure found in the universe. Two or more atoms together make a molecule.
Answer to Problem 1TYU
Correct answer:
The reactivity of an atom arises from the existence of unpaired electrons in the valence shell.
Therefore, option (B) is correct.
Explanation of Solution
Reason for the correct statement:
Unpaired electrons in a valence shell are unstable in nature and in order to become stable, an atom can lose or gain electrons and becomes reactive.
Option (B) is given as “the existence of unpaired electrons in the valence shell”.
As “the reactivity of an atom arises from the existence of unpaired electrons in the valence shell”, it is the right answer.
Hence, option (B) is correct.
Reasons for the incorrect statements:
Option (A) is given as “the average distance of the outermost electron shell from the nucleus”.
If the distance of the outermost electron shell is large, then there would be a lesser nuclear effective charge. Thus, an electron can easily be expelled out of its shell. Thus, it does not cause an atomic reactivity. Hence, it is the wrong answer.
Option (C) is given as “the sum of the potential energies of all the electron shells”.
The sum of the potential energies of all the electron shells affects only the chemical properties of the atom and is not involved in its reactivity. Hence, it is the wrong answer.
Option (D) is given as “the potential energies of the valence shell”.
The potential energy of the valence shell decides which shell would get the electron first and is not involved in its reactivity. Hence, it is the wrong answer.
Hence, options (A), (C), and (D) are incorrect.
The number of electrons present in the outermost shell of an atom determines the atom reactivity.
Want to see more full solutions like this?
Chapter 2 Solutions
CAMPBELL BIOLOGY IN FOCUS-MOD.MASTERING
Additional Science Textbook Solutions
Biological Science (6th Edition)
College Physics: A Strategic Approach (3rd Edition)
Laboratory Manual For Human Anatomy & Physiology
SEELEY'S ANATOMY+PHYSIOLOGY
Biology: Life on Earth with Physiology (11th Edition)
- What are intrinsically disordered proteins, and how might they be useful for a living system?arrow_forwardWhat are Amyloid Fibrils? What biological functions are these known to perform?arrow_forwardHow do histamine and prostaglandins help in the mobilization of leukocytes to an injury site? What are chemotactic factors? How do they affect inflammation process?arrow_forward
- Compare and contrast neutrophils and macrophages. Describe two ways they are different and two ways they are similar.arrow_forwardDescribe the effects of three cytokines (not involved in the initial inflammation response). What cells release them?arrow_forwardDescribe activation of helper T cells or cytotoxic T cellsarrow_forward
- Compare and contrast MHC 1 and MHC 2. Describe two way they are different and two ways they similar including how they are used in antigen presentation.arrow_forwardDescribe two antimicrobial properties of the skin.arrow_forwardDescribe how the inflammation response starts including the sentinel cells and the chemicals involved. How do pathogens trigger the response particularly in the skin?arrow_forward
- How does complement promote the immune response? Describe three waysarrow_forwardWhich of the following is not a possible mechanism for autoimmunity? Select one: A. Abnormal expression of MHC II molecules in non-antigen-presenting cells B. Activation of polyclonal B cells C. Polymorphism of HLA alleles D. Molecular mimicry E. Release of sequestered antigensarrow_forwardWRITTEN WORK 3: NON-MENDELIAN GENETICS Part A: Complete the Punnett square and calculate for the probability of genotype and phenotype. i i Genotype: Phenotype: 08:55arrow_forward
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax CollegeBiology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning