atoms, elements and compounds. Flashcards
what are all substances made out of?
atoms.
what is an atom?
smallest part of an element that can exist.
what is an element?
substance that contains only one sort of atom.
how many different elements are there?
around 100.
where are elements displayed?
periodic table.
what are elements represented by on the periodic table?
different chemical symbols.
what are most substances?
compounds.
what is a compound?
contains atoms of 2 or more elements which are chemically combined in fixed proportions.
what is the term used when compounds are represented by a combination of number and chemical symbols?
chemical formula.
what do scientists use chemical formulas to show?
different elements in a compound.
how many atoms of each element one molecule of the compound contains.
which side are the products and reactants in a chemical formula?
products: right- new substance.
reactants: left.
