energy Flashcards
(20 cards)
how is energy conserved?
in chemical reactions
what happens to the energy in the universe after a chemical reaction?
it stays the same
what is an exothermic reaction?
a reaction that transfers energy from the system to the surroundings
what happens to the surroundings in an exothermic reaction?
it increases/ gets hotter
what are some examples of exothermic reactions? (3)
combustion
respiration
displacement
what are some everyday uses of exothermic reactions? (2)
hand warmers
self heating cans
what reaction is an increase in temperature?
exothermic
what is an endothermic reaction?
a reaction that takes energy in from surroundings to the system
what happens to the surrounding in an endothermic reaction?
it decreases/ gets colder
independent variable
changes
dependant variable
measure
control variable
keep the same
what is resolution?
the smallest change in a quantity that gives a change in a reading
how do you estimate uncertainty?
consider the resolution
what is the equation for percentage uncertainty?
uncertainty / volume measured X100
what is a systematic error?
the measurement is wrong by the same amount every time
in a chemical reaction what must energy be supplied for?
breaking bonds
in a chemical reaction whag must energy be released for?
forming bonds
what are examples of endothermic reactions? (2)
photosynthesis
thermal decomposition reactions
what is an everyday use of endothermic reactions?
ice pack
