Chemistry Study Questions Flashcards
What is energy? What is the difference between kinetic and potential energy?
Basis of all chemistry. Kinetic energy is actively being used and potential energy is stored energy.
What are the 5 major forms of energy?
Chemical, Thermal, Radiant, Mechanical and Electrical
What does each energy do?
Chemical: fuels division, created by anabolism; released by catabolism.
Mechanical: movement of stuff; produced by muscular system
Thermal: Heat; waste energy
Electrical: Movement of charged particles; used by neurons and muscles
Radiant: visible light
Why is chemical energy the form that humans use to power reactions? Why is the conversion and use of chemical energy so inefficient? Where does the extra energy go?
Chemical energy is stored in our atoms as potential energy and has to be converted into kinetic energy in order to be used. The extra energy is wasted, converted into thermal energy.
How does thermal energy influence reaction rates? Why is the preferred rate different between different organisms? Where does the thermal energy come from?
Thermal energy powers chemical reactions and the rate of reactions are based on how much thermal energy is wasted. Thermal energy comes from heat.
What is matter? What makes up atoms? What are the differences and similarities between elements and ions?
Matter is the substance made up of various types of particles that occupies physical space. Atoms are made up of protons, neutrons and electrons. Elements and ions are both comprised of electrons, in the case of an ion it is due to an unequal number of electrons.
Why is an atom without a full outer shell “unhappy”? What can it do to be happy? What happens when a chemical bond happens?
An atom without a full outer shell is considered unstable. They can accept electrons to become happy and fill that valence shell.
How does an ionic bond form? How does a covalent bond form? What determines which kind of bond forms?
Ionic bonds form when electrons are transferred from one atom to another. Covalent bonds form when the electronegativities of two atoms is too small for an electron transfer to occur to form ions. The electronegativities of the elements determine the type of bond formed.
What is a polar covalent bond? What is a hydrogen bond? What kind of atoms form these bonds? Why are hydrogen bonds not chemical bonds?
A covalent bond where electron density is unevenly shared between two bonded atoms who already have differences in electronegativity.
Attraction between two atoms that already participate in other chemical bonds. One atom is hydrogen while the other may be an electronegative atom.
Hydrogen, oxygen, chlorine or fluorine
It is a dipole to dipole interaction, not a true chemical bond since it is so weak.
What is the difference between acids and bases? What does pH measure? How does the pH scale work? Why are protons so useful in living things?
An acid contains an increased amount of hydrogen and a base does not. pH is a measure of a relative amount of free hydroxyl ions in the water. Protons determine the identity of the atom itself. Different number of protons, determine different types of atoms.
What is a solvent? How do things dissolve? What are the benefits of ionic chemicals? What are the benefits of covalent molecules?
A solvent is a substance that dissolves other solutions. They dissolve when the attraction between the particles of the solvents and solute are strong enough to overcome the attractions of the particles of the solute for one another.
What is a lipid? What are they used for? What are the parts of a lipid? Why are lipids not usually soluble in water?
A lipid is a fat that is used for energy storage. Two fatty acids, a glycerol and a phosphate group. Water cannot adhere to lipid because it is not charged.
How does human physiology rely on all bonds to function?
Hydrogen bonds allow water to act as a solvent, and DISSOLVE polar molecules and ions.
Dissolved ions can be used for ENERGY STORAGE AND signaling
Covalent bonds create stable molecules that have unique shapes, perform many different functions and can be VERY large.`
Why is carbon so useful in making molecules? Why can carbon make 4 bonds? Why can oxygen make only 2? What are the primary atoms of organic molecules?
Carbon’s ability to form stable with many elements, allowing for near infinite combinations. Carbon can make 4 bonds due to its 4 shareable outer electrons; Carbon, Hydrogen, Nitrogen, and Oxygen.
MONOMER AND POLYMER OF PROTEINS
Amino acids; Polypeptide
