Transcription 24.11.2025, 18:34:33

Notes

• Atomic Structure and Periodic Table Hull's School Zurich's English College Homework Block The order of elements is based on increasing atomic numbers from left to right. Groups are vertical columns numbered 1, 2, 3, 4, 5, 6, 7, 0. Periods are horizontal rows numbered 1 through 7. The number of protons in an atom equals its atomic number. Electrons are equal in number to protons. Neutrons are calculated as: mass number minus atomic number. The arrangement of electrons is called the electronic configuration. The first shell can hold a maximum of 2 electrons. The second shell can hold up to 8 electrons. The third shell can hold up to 8 electrons for the first 20 elements. Elements in the same group have the same number of electrons in their outermost shell. The outer shell electron count equals the group number. The period number indicates the number of electron shells. • Noble Gases and Properties Noble gases belong to group 0. They have 8 electrons in their outer shell, except helium, which has 2. They do not lose or gain electrons during reactions. • Metals and Non-metals Metals: - Conduct electricity. - Form acidic oxides. ...