Atomic Structure (C1.2) Flashcards
Element
pure substance that consists entirely of one type of atom
molecule
A group of atoms bonded together by chemical bonds.
What is inside an atom
protons, neutrons, electrons
Subatomic particles relative mass and charge
proton- 1 +1
electron-0.0005 -1
neutron- 1 0
Atomic symbol
the symbol is one or two letters chosen to represent an element (“H” for “hydrogen,” etc.)
chemical symbol
A one or two letter representation of an element
mass number
the sum of the number of neutrons and protons in an atomic nucleus
atomic number
the number of protons in the nucleus of an atom
isotope
atoms with the same number of protons and electrons but different number of neutrons
ion
A charged particle
How are ions formed
when atoms lose or gain electrons
What did John Dalton do
Developed the atomic theory
What is the atomic theory
all matter is composed of small, indestructible particles called atoms
all atoms of an element are identical
different elements contain different atoms
What did JJ Thompson do?
Nucleus and protons
atom has a positively charged nucleus containing most of its nucleus
outside the nucleus electrons orbit it like a solar system
What did Bohr do?
adapted the nuclear model by suggesting that electrons orbit the nucleus at specific distances.
