13 topics with concise reviews: definitions, key facts, and class questions.
This chapter is dedicated to the fundamental principles of chemistry, without which it is impossible to understand complex biochemical processes in the human body. We will analyze the subject matter of chemistry, clarify how individual substances differ from mixtures and solutions, and touch upon an aspect of utmost importance for future physicians—the toxicity and safety of chemical compounds.
Here you will refresh your knowledge of atomic structure and chemical elements, and learn to navigate the Periodic Table with ease. The section covers in detail the rules for calculating atomic and molecular mass, the principles of writing chemical formulas, as well as the "architecture" of matter: the spatial structure of substances, valence, and coordination number.
During the first seminars and colloquia, instructors are strictest about the fundamentals: the electronic structure of the atom, and the ability to determine valence and coordination number in complex compounds. Without a clear understanding of these concepts (rather than mere rote memorization of formulas), further study of bioorganic chemistry will become torture. We break down the complex simply and to the point.
What is the main difference between chemistry and other natural sciences?
Unlike physics or mechanics, chemistry is focused precisely on the transformations of substances and changes in their nature when interacting with each other or under the influence of the external environment.
Is salt water a substance?
No, salt water is a homogeneous mixture. Its properties are non-constant and depend on the concentration of dissolved salt, whereas a pure chemical substance always has a constant composition.
Is it possible to obtain an absolutely pure substance in the laboratory?
No, this is fundamentally impossible. Any real chemical sample, even of the highest grade of purity, will contain at least a minimal amount of impurities.
Are there any absolutely safe substances?
No, practically any substance can cause poisoning if used improperly or if the dose is exceeded. Only water and table salt are considered conditionally harmless.
Do atoms disappear during chemical reactions?
No. During chemical transformations, the atom is neither divided nor destroyed. Only the distribution of electrons between atoms changes, while the nucleus itself always remains unchanged.
What is the essence of the analogy method in studying element chemistry?
This method allows predicting the chemical properties of a compound if you know the properties of its group analogue in the Periodic Table (for example, the properties of rubidium are predicted based on potassium).
Master the entire topic in the "Chemistry" course
This is a summary. The course covers everything tested in classes and exams.
3,009 pages of study guides for all topics
Assignments and quizzes after every topic — just like in a colloquium