Mass / Atomic No & Isotopes

• in an atom, the number of electrons is equal to the number of electrons is equal to the number of protons in the nucleus
• atoms have no overall charge
• al atoms of a particular element have the same number of protons
• the number of protons in an atom is called its atomic number
• the total number of protons and neutrons in an atom is called the mass number
• mass number is the top one
• atoms of the same element can have different numbers of neutrons this is an isotoope
• atoms turn into positive ions if they lose one or more outer electrons