All About Atoms!

THE ATOM AN ATOM IS THE SMALLEST UNIT OF MATTER IS THE “BUILDING BLOCK “OF ALL ELEMENTS HAS THE SAME PROPERTIES AS THE ENTIRE ELEMENT COMPOSED OF TWO PARTS: 1) A NUCLEUS IN THE CENTER 2) SHELLS/ORBITS SURROUNDING THE NUCLEUS MADE UP OF 3 SUBATOMIC PARTICLES: PROTONS NEUTRONS ELECTRONS

PROTONS (P+) NUMBER OF PROTONS = ATOMIC NUMBER LARGE SUBATOMIC PARTICLE FOUND IN THE NUCLEUS HAS A POSITIVE CHARGE (+) CONTRIBUTES TO MASS OF ATOM P+ NUMBER OF PROTONS = ATOMIC NUMBER

NEUTRONS (N0) PROTONS + NEUTRONS = ATOMIC MASS LARGE SUBATOMIC PARTICLE FOUND IN THE NUCLEUS OF AN ATOM HAS A NEUTRAL CHARGE (ZERO, 0 CHARGE) CONTRIBUTES TO MASS OF ATOM P+ N0 PROTONS + NEUTRONS = ATOMIC MASS

ELECTRONS (e-) PROTONS = ELECTRONS IN A NEUTRAL, OR BALANCED ATOM, SMALL SUBATOMIC PARTICLE FOUND IN SHELLS/ORBITS SURROUNDING THE NUCLEUS HAS A NEGATIVE CHARGE (-) DOES NOT CONTRIBUTE TO THE MASS OF THE ATOM DETERMINES THE OVERALL CHARGE OF THE ATOM electrons P+ N0 shells/orbits IN A NEUTRAL, OR BALANCED ATOM, PROTONS = ELECTRONS

1st shell can hold up to 2 electrons 2nd shell can hold up to 8 electrons 3rd shell can hold up to 18 electrons

Bohr Model Bohr Model for Beryllium Used to diagram atomic arrangement and particle placement Model is one-dimensional even though real-life atoms are 3-D 4 P+ 5N0 = electrons (e-)