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Chapter 2 Questions
Question | Answer |
---|---|
Define matter | anything that has weight and takes up space |
List the four most abundant elements in the human body | oxygen, carbon, hydrogen, and nitrogen |
Explain why a complete atom is electrically neutral | the number of electrons outside the nucleus equals the number of protons |
Distinguish between atomic number and atomic weight | atomic number is the number of protons; atomic weight is the number of protons and neutrons |
Define isotope | atoms that have the same atomic number but different atomic weights |
Explain how electrons are distributed within the electron shells of atoms | first shell-2, second shell-8, third shell-8 |
An ionic bond forms when | ions with opposite charges attract |
A covalent bond forms when | atoms share electrons |
Explain how a hydrogen bond forms | the attraction of the positive hydrogen end of a polar molecule to the negative nitrogen or oxygen end of another polar molecule |
Define electrolyte, acid, base, and salt | electrolyte-substances that release ions in water/// acid- substance that releases hydrogen ions///base-substance that releases ions that can combine with hydrogen ions///salt-substance formed by the reaction between and acid and a base |
Explain pH and how to use the pH scale | |
Distinguish between inorganic and organic chemicals | organic have carbon and hydrogen///inorganic are all others |
Distinguish between elctrolytes and nonelectrolytes | electrolytes are inorganic substances that dissolve in water///nonelectrolytes are organic compounds that dissolve in water and do not release ions |
Describe the functions of water and oxygen in the human body | transports chemicals and oxygen///both used for transport |
List several ions that cells require and identify their functions | Sodium, Chloride, Potassium, Calcium, Magnesium, Phosphate, Carbonate, Bicarbonate, Sufate///play roles in metabolism, helping maintain proper water concentrations, pH, blood clotting, bone development, energy transfer in cells, etc |
List at least three functions of proteins | structural materials, energy sources, and hormones |
Identify the four levels of protein structure | primary, secondary, tertiary, and quarternary |
Describe the general characteristics of nucleic acids | consists of a 5 carbon sugar, a phosphate group, and one of several nitrogen-containing organic bases called nitrogenous bases |