The three SUBATOMIC PARTICLES are

The three SUBATOMIC PARTICLES are Proton Electron Neutron

PROTON Symbol charge location Mass +1 p+ in the nucleus same as neutron

e- -1 ELECTRON Symbol charge Location Mass outside the nucleus tiny; 1/2000 of a proton

Force inside atoms • Electrons are bound to the nucleus by the attractive force between electrons (-) and protons (+).

NEUTRON Symbol n charge 0 Location in the nucleus Mass same as proton

Element Card 82 Pb Lead 207.2 Atomic Number Element Symbol Element Name Atomic Mass

ATOMIC NUMBER – equals the number of protons in an atom of an element Element Card Atomic Number 82 Pb Lead 207.2

ATOMIC NUMBER – equals the number of protons in an atom of an element

BALANCING CHARGE * the +1 charge of a proton exactly equals the -1 charge of an electron * all atoms are electrically neutral * in an atom the number of protons equals the number of electrons

MASS NUMBER– the sum of the protons and neutrons in the nucleus 82 Pb Lead 207.2 Atomic Mass

The number of neutrons = mass number – atomic number

ISOTOPES – atoms of the same element have different numbers of neutrons

To summarize isotopes: They are atoms of the same element They have the same number of protons . They have different number of neutrons . They have different mass numbers. They have the same chemical and physical properties.

The three SUBATOMIC PARTICLES are