atoms

• what's the mass of electrons

  1/1836
• what's the mass of protons

  1
• what's the mass of neutrons

  1
• charge of protons

  +1
• charge of electrons

  -1
• charge of neutrons

  0
• where are electrons located in an atom

  electron shells
• where are protons located in an atom

  nucleus of atom
• where are neutrons located in the atom

  nucleus of atom
• why do atoms have a overall neutral charge

  the subatomic particles charge cancels (protons and electrons)
• where is most of the mass of an atom concentrated

  nucleus
• mass number = number of protons + neutrons
• isotopes : different atoms of the same element with the same number of protons but different number of neutrons
• atomic number = number of protons/electrons