The document discusses the structure of atoms and properties of subatomic particles. It defines protons, neutrons, and electrons, noting their charges and locations. It explains that the atomic number is the number of protons and determines the element, while the mass number is the total of protons and neutrons. Isotopes are defined as atoms of the same element that have different numbers of neutrons and mass numbers.

1. The Structure of An Atom Properties of Subatomic Particles Comparing Subatomic Particles Atomic Number and Mass Isotopes

2. Sub Atomic Particles Protons- +1 positive charge found in nucleus Electrons- -1 found outside nucleus Neutron- no charge found inside the nucleus

3. Comparing Subatomic Particles 1 0 n Neutron 1 1+ p+ Proton  0 1- e- Electron Mass Charge Symbol Particle Properties of Subatomic particles

4. Atomic Number and Mass Number Atomic Number equals the number of protons in the nucleus Different elements have different atomic numbers The mass number of an element is the number of protons+the number of neutrons

5. Number of Neutrons No. Neutrons= mass no.-atomic no.

6. Isotopes Isotopes are atoms of the same element (same number of protons) but with varying no. of neutrons Isotopes have different mass numbers but are still the same element