chemistry Flashcards
what is an element
a substance which cannot be broken down into similar substances by chemical methods.
what is a compound
a substance formed when two or more elements combine chemically with eachother
True or false: elements in a compound will always be present in a fixed ratio
true
what is a mixture
two or more substances
what are three sub-aomic particles
protons, neutrons and electrons
how many protons does an atom contain
6
what is an isotope
an atom that has the same amount of protons and electrons but different amount of neutrons
what is a molecule
when two or more elements react together
what is a diatomic molecule
elements that exist in nature as molecules
what does the formula compound show
name of compound
elements that make it up
ratio
what is the first group in the periodic table
alkali metals
what are the two sections involed in a chemical reaction
reactants and products
what does the law of conservation of mass state
matter cannot be created nor destroyed only transferred from one object to another
