BiochemistryLesson 1 of 3 in the course Chemistry of Life

Atomic Structure, Isotopes, Electron Shells, and Biological Bonds

5 flashcards · 5 quiz questions · 5 match pairs · 5 fill-in sentences · English

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Summary

Living things are made of matter, and matter is built from elements and atoms. Understanding these building blocks helps explain how the materials of life are organized, from tiny particles to entire organisms.

Matter is anything that occupies space and has mass. All matter is composed of elements, which are substances that cannot be broken down or transformed chemically into other substances. Each element has distinctive properties and is represented by a chemical symbol, such as H for hydrogen, O for oxygen, C for carbon, and Na for sodium.

All flashcards

Mass number
The total number of protons and neutrons in an atom.
Radioisotope
An unstable isotope that releases energy or particles as it changes toward a more stable form.
Cation
A positively charged ion formed when an atom loses electrons.
Hydrogen bond
A weak attraction between a partially positive hydrogen and a nearby partially negative region.
Nonpolar covalent bond
A covalent bond in which electrons are shared equally or nearly equally.

Quiz questions

  1. An atom has a mass number of 23 and an atomic number of 11. How many neutrons does it have?Answer: 12
  2. What distinguishes isotopes of the same element?Answer: They have different numbers of neutrons.
  3. What does the half-life of a radioactive isotope measure?Answer: The time for half of the original quantity to decay.
  4. How does an ionic bond form?Answer: Oppositely charged ions attract after electrons transfer between atoms.
  5. What makes a covalent bond polar?Answer: The bonded atoms share electrons unequally, creating partial charges.

Based on Concepts of Biology by Samantha Fowler, Rebecca Roush, James Wise (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.

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