The required questions are the official questions at the end of the college entrance examination, and the contents appearing in the test papers are transported to the exercise books for students' reference and brushing, which is more practical, so the required questions are the best test papers in the chemistry exercise books of senior two.

Chemistry is a basic natural science that studies the composition, structure, properties, transformation and application of substances at the atomic and molecular levels. It originates from life and production practice, and develops with the progress of human society. Different from particle physics and nuclear physics, chemistry studies the physical structure of atoms, molecules and ions (groups) and the interaction between chemical bonds and intermolecular forces. Its scale is the closest to the micro-world, so its natural laws are also most closely related to the physical and chemical properties of substances and materials in the macro-world where human beings live. As an important bridge between micro and macro material world.