Why Is Chemistry Important on the HESI EXAM?
Basic chemistry knowledge will help you understand important concepts in nursing such as pharmacology, fluid and electrolyte balance, and drug interactions in the body. A good background in chemistry now makes many of the future nursing classes much easier to understand.
Core Concept 1 Atomic Structure
Understanding the basic building blocks of matter is important for almost every other topic in chemistry.
- Atoms: The smallest unit of matter made up of protons, neutrons, and electrons.
- Protons: are positively charged particles located in the nucleus of the atom.
- Neutrons: neutral particles located in the nucleus with the protons.
- Electrons: Particles with a negative charge that circle the nucleus and take part in chemical bonding.
Core Concept 2: The Basics of the Periodic Table
You do not have to memorize the whole periodic table, but it helps to know how it is laid out.
- The elements are arranged according to atomic number, the number of protons in the atom.
- Elements in the same group (column) have similar chemical properties.
- The periods (rows) are arranged left to right in increasing atomic number.
- Common elements relevant to healthcare are worth reviewing, particularly the role of sodium, potassium, calcium and chlorine in bodily functions.
Core Concept 3: Chemical Bonding
Knowing how atoms bond together explains how molecules form and interact.
- Ionic bonds – form when electrons are transferred from one atom to another, often creating charged particles called ions.
- Covalent bonds – bonds between atoms that share electrons. Common in many organic molecules.
- Hydrogen bonds – weaker bonds that are important in the unique properties of water and in biological molecules.
Core Concept 4: Acids, Bases, and pH
This is particularly relevant to healthcare because the body has a very specific pH balance.
- Acids - substances that donate hydrogen ions and have a pH of less than 7. Bases - substances that accept hydrogen ions and have a pH of greater than seven.
- PH scale (0 to 14, 7 is neutral, human body usually has about 7.4 pH).
- Buffers - substances that help the body resist drastic changes in pH, which is important to the maintenance of homeostasis.
Core Concept 5: Solutions, Concentration, and Dilution
These concepts tie directly into dosage calculations that you will encounter later on the HESI exam.
- Solute and solvent the material being dissolved is the solute. The material doing the dissolving is the solvent .
- Concentration — the quantity of solute in a given quantity of solvent.
- Dilution - The process of making a solution less concentrated by adding more solvent.
How to Study Chemistry Well
- Emphasize healthcare applications. Whenever possible, link abstract chemistry concepts to real-world nursing situations.
- Use diagrams for atomic structure and bonding as it is easier to understand the concepts with diagrams.
- Practice pH specific questions, as this is a concept that directly connects to body systems you will learn throughout nursing school.
- Also, review basic math and chemistry. Concepts of concentration and dilution typically involve simple calculations.
- Break topics into manageable small sections, not try to review all of chemistry in one sitting.
Common Mistakes to Avoid
- Relearning a whole chemistry course instead of just the important, high-yield concepts.
- Not doing the pH and acid-base section, even though it is very relevant to healthcare and future classes.
- Studying chemistry alone – missing important links to biology, pharmacology and body system function.
- Memorizing things instead of understanding the underlying logic behind each concept.
Concluding Words
You do not need to memorize all of college-level chemistry to do well on the HESI exam, but you do need to understand the basic concepts that are directly related to healthcare and nursing practice. You can streamline your review process by focusing on atomic structure, chemical bonds, pH balance, and basic solution concepts rather than feeling overwhelmed by the subject. This basic knowledge of chemistry will also help you in pharmacology and other science-based courses throughout your nursing education.
