Study guide: chemical building blocks Flashcards
atom
smallest unit of an element that has all the chemical properties of that element; atoms are the building blocks of matter
matter
anything that has mass and takes up space
chemical bond
a force that holds atoms together
element
a pure substance containing only one kind of atom
compound
two or more elements that are chemically combined
Independent variable
the variable that is changed on purpose in an experiment
Exothermic reaction
a chemical reaction that releases energy, usually in the form of heat or light ex: lighting a fire
endothermic reaction
a chemical reaction that absorbs energy
ex: frying an egg, baking a cake
what is a pure substance
a substance that is made up of only one type of matter (one type of element or one type of compound
ex: water, gold
what is an element
a pure substance containing only one kind of atom
ex: iron, hydrogen, oxygen, copper
dependent variable
what is mesaured or observed in an experiment
compound
two or more elements chemically combined
ex: water gulcose
volume
amount of space occupied by matter
mass
amount of matter in an object
density
amount of mass per unit volume
