Unit 2- physical and chemical changes Flashcards
(27 cards)
energy
capacity for doing work or producing heat
physical change
does not change the identity of a substance
chemical change
forming something new with new properties
evaporation
vaporization at the surface of a liquid
endothermic
process that absorbs heat from the surroundings
exothermic
process that releases heat into the surroundings
law of conservation of energy
energy is neither created or destroyed
heat
energy that transfers from one object to another because of a difference in temperature
kinetic energy
energy of motion
potential energy
stored energy
temperature
measurement of heat or kinetic energy
chemical
a substance with a chemical formula
chemical reaction
change in which one or more reactants change into new products
states of matter
solid, liquid or gas
reactant
substance(s) that start a chemical reaction
product
substance(s) that are produced in a chemical reaction
matter
anything that has mass and takes up space
physical property
quality of a substance that can be observed without changing the substances’ composition
chemical property
ability of a substance to undergo a chemical reaction
atom
smallest part of an element
pure substance
substances with a unique set of physical and chemical properties - element or compound
element
simplest form of matter that cannot be broken down into simpler substances
molecule
group of atoms held together with covalent bonds
compound
made of 2 or more kinds of atoms chemically combined in a fixed proportion
