fundamentals of chemistry Flashcards
What is matter?
any substance that has mass and occupies space; exists in three forms: solid, liquid, gas
What are elements?
building blocks of matter; 96% of our body is carbon, oxygen, nitrogen, hydrogen
What is an atomic number?
number of protons
What is the mass number?
number of protons of neutrons
What is an isotope?
structural variations of an element; protons are the same but neutrons vary
What is the atomic weight?
average weight of all isotopes of an atom
What are atoms?
smallest unit of elements; consists of central nucleus (protons and neutrons) surrounded by ring(s) of electrons
What are the 3 characteristics of an atom?
- up to 7 rings/shells/orbitals containing electrons, with maximum allowed per ring
- valence shell: outermost shell with highest potential energy
- ion: an atom that has gained or lost electrons; includes salts, electrolytes, minerals
What is radioisotopes?
gives off radiation as they decay; can be harmful but also used in medicine
What is a chemical bond?
two or more atoms held together and stores potential energy
What is an ionic bond?
atoms completely transfer; mostly salts
What is a covalent bond?
atoms share electrons
What is a nonpolar covalent bond?
equal sharing of electrons
What is a polar covalent bond?
unequal sharing of electrons
What is a hydrogen bond?
weak chemical bond involving hydrogen
What is energy?
has no mass or space, but gives matter the ability to do work
What is kinetic energy?
energy of motion
What is potential energy?
stored energy
What is the law conservation of energy?
energy cannot be created or destroyed, only converted
What are chemical reactions?
occurs when chemical bonds are formed or broken
What is an endergonic?
absorbs energy
What is an exergonic?
releases energy
What are the types of chemical reactions?
synthesis, decomposition, exchange
What is synthesis?
combine small molecules to make larger molecules (a+b=ab)
What is anabolic process?
consumes energy to make large molecules
What is decomposition?
large molecule breaks into smaller molecules (ab=a+b)
What is the catabolic process?
releases energy as it breaks down molecules
What is an exchange?
two molecules exchange atoms (ab+cd=ad+cb)
What is oxidation - reduction?
electrons exchanged between reactants (cellular respiration)
What is temperature?
increase in temp increase reaction rate
What is concentration?
higher concentration increases reaction rate
What is particle size?
smaller size increases reaction rate
What are molecules?
2 or more atoms of the same type of atom (h2, o2, h2o)
What are compounds?
2 or more types of atoms bonded together (h2o, nacl, c6h12o6)
What is a mixture?
2 or more substances blended together with no chemical changes (sugar water)
What is a solution?
one substance dissolved into another
What is a solute?
dissolved substance (sugar)
What is a solvent?
substance in which a solute is dissolved (water)
What is a colloid?
mixture where particles remain permanently mixed with solvent (jello cytosol)
What is a suspension?
mixture where particles separate upon standing (ketchup and blood)
What are acids and bases?
substances that alter the hydrogen concentration (h+) of a solution
What is an acid?
substances that increases the h+ concentration of a solution
What is a base?
substance that decreases the h+ concentration of a solution
What is a pH scale?
measures h+ concentration
What is the pH scale?
pH of 7.0 is neutral, pH less than (<) 7.0 is acidic, pH greater than (>) 7.9 is basic (alkaline)
What are buffers?
substances that minimizes h+ charges when acid/base is added
What is the pH of human blood?
7.35 to 7.45
