Questions and Answers
How many of the 92 naturally occurring elements are normally found in the human body?
26
To change an atom into an atom of a different element, you would need to change the number of?
Protons in the atom
The atomic number of an element is determined by the number of?
Protons
Helium has two protons and therefore has how many electron shell(s)?
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What is an anion?
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What is a cation?
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Ionic compounds normally exist in which physical state?
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What is considered a molecule and a compound?
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What is a suspension?
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What is used as a basis for the pH scale?
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What is one characteristic shared by all organic molecules?
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Compounds that have the general formula CH2O are?
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Which pentose sugar is found in DNA?
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Which of the following are double-ringed purines?
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What are fibrous proteins?
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What are enzymes?
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Conversion of energy from potential to kinetic will generally release what?
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Many reactions in the body consist of both synthesis and decomposition reactions and are called?
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If energy is required to make a reaction occur, it is a what kind of reaction?
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Catabolism is to anabolism as what is to what?
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Stored energy that is available to do work is called what?
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Identify this reaction: AB < --- > A + B
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Products with less energy than the initial reactants are produced in what kind of reaction?
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The total amount of energy at the beginning of a reaction is the same at the end of the reaction.
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The energy required to start a chemical reaction is called?
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In oxidation-reduction reactions, the reduced substance gains _____ and ______.
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If energy is released as a reaction occurs, what kind of reaction is it?
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In a reaction, the loss of one or more electrons from a molecule is called?
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What term refers to all chemical reactions that occur in the body?
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Study Notes
Elements and Atoms
- 92 naturally occurring elements exist on Earth; 26 are typically found in the human body.
- Changing an atom into a different element requires altering the number of protons in the atom.
- The atomic number of an element is based on the number of protons it possesses.
Electron Shells and Ions
- Helium, with two protons, has 1 electron shell.
- Anions are negatively charged ions, while cations are positively charged ions.
- Ionic compounds commonly exist in solid state.
Compounds and Suspensions
- A molecule and a compound example is H2O (water).
- Suspensions involve materials that mix with a liquid but eventually settle out over time.
pH and Organic Molecules
- The pH scale is based on the concentration of H+ ions, measured in moles per liter.
- All organic molecules share the characteristic of containing a carbon skeleton.
Carbohydrates and Nucleic Acids
- Compounds with the general formula CH2O are classified as carbohydrates.
- Deoxyribonucleic acid (DNA) contains the pentose sugar deoxyribose.
- The purines adenine and guanine are double-ringed structures.
Proteins and Enzymes
- Fibrous proteins are insoluble in water, featuring long parallel polypeptide chains.
- Enzymes, which are usually proteins ending in -ase, act as catalysts to speed chemical reactions without being consumed in the process.
Energy and Chemical Reactions
- Energy conversion from potential to kinetic typically releases heat.
- Reactions may consist of synthesis and decomposition, categorized as exchange reactions.
- Synthesis reactions require energy input to occur.
Energy Relationships
- Catabolism relates to anabolism in context of exergonic vs. endergonic reactions.
- Potential energy is stored energy that can perform work.
- Reversible reactions can be represented as AB <--- A + B.
Reaction Types
- Endergonic reactions produce products with less energy than reactants.
- The principle that total energy remains constant throughout a reaction is affirmed; initial energy equals final energy.
- Activation energy is the energy necessary to initiate a chemical reaction.
Oxidation-Reduction Reactions
- In oxidation-reduction reactions, the reduced substance gains electrons and energy.
- Exergonic reactions release energy as they progress.
- Oxidation refers to the loss of electrons from a molecule, a process associated with negative charges from oxygen.
Overall Chemical Processes
- Metabolism encompasses all chemical reactions occurring within the body.
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Test your understanding of key terms from Chemistry Chapter 2 with these flashcards. Learn about elements, atomic structure, and the fundamentals that shape our understanding of matter. Perfect for revision and enhancing your chemistry vocabulary.