chemistry Flashcards
(8 cards)
what are the four signs of a chemical reaction?
colour change
gas being produced
solid forming
energy change
what is the difference between exothermic and endothermic reaction?
during an exothermic heat energy is released
during endothermic heat energy is taken in
what happens in any chemical reaction?
a new substance is formed
what factors can affect rate of reaction?
temperature
concentration
surface area/ particle size
use of a catalyst
what formula is used to calculate an average rate of rection?
change in quantity
____________________
change in time
elements in the same group in periodic table have what?
similar chemical properties
how to find neutrons number?
the mass number of an atom is equal to the number of protons added to the number of neutrons
what are isotopes?
atoms with the same atomic number but different mass number
