1 - PRINCIPLES OF CHEMISTRY
Atoms - 1 - Nucleus
- Middle of atom
- Protons and neutrons
- Positive charge
- Contains most of the mass of the atom
- Move around nucleus in shells
- Negatively charged
- Cover a lot of space
- Size of orbit depends on size of atom
- Virtually no mass
Protons = heavy and positive Neutrons = heavy and neutral
Electrons = small mass, negative
Number of electrons = number of protons (in neutral atom/not isotope) -
- Neutral atoms = no charge overall
- Charge on electrons is same size as the charge on protons (but opposite)
- Electrons added/removes - atom becomes a charged ion
- Atomic number = no. of protons
- Mass number = protons + neutrons
- No. of neutrons = mass number - atomic number
- Groups of atoms (joined together)
- Can be one element (H2, N2) or more than one element (H2O, CO2)
- Held together by covalent bonds
No comments:
Post a Comment