part4-+Atoms&Elements,+subatomic+Particles,+&&+chemical+sybols+&+formula.

Atoms && Elements

atoms- the smallest unit of matter that can take part in a chemical change.

elements- a type of pure substance that can not be broken down into simpler parts by ordinary chemical means (e.g, oxygen,gold.)

Subatomic Particles- particles such as protons neutrond, and electrons called subatomic because they are smaller then atoms.

Bohr Model :



Chemical Symbols & Formula- a formula that uses symbols and numbers to reresent the elements in a pure sybstance (e.g, H2O is the chemical formula for water.