chemical database online measuring container - measuring cylinder When measuring liquid volume, the measuring cylinder must be placed smoothly. The line of sight is level with the scale line and the lowest point of the liquid concave surface in the measuring cylinder. The cylinder cannot be used for heating and cannot be used as a reaction vessel. A measuring cylinder with a measuring range of 10 ml can generally only read 0.1 ml. (3) Weighing device - pallet balance (for rough weighing, generally accurate to 0.1 grams.) Note: (1) First adjust the position of zero (2) weighing objects and weights to "left object right code". (3) Weighing objects can not be placed directly on the tray.
Junior high school chemistry knowledge point summary one, basic concepts two, basic knowledge, theory three, the common name of the substance and its corresponding chemical formula and chemical name four, the color of the common substance state five, the solubility of the substance six, chemistry seven, problem-solving skills and explanations eight, junior high school chemistry "three" nine, chemistry "must" and "not necessarily" Eleven, basic chemical reaction junior high school chemical law summary of junior high school chemistry Basic concepts and principles of junior high school chemical elements and compounds (a) Junior high school chemistry general review -- elemental and compounds of the elements (B) Junior high school chemistry general review -- Chemical experiment comprehensive junior high school review -- chemical calculation comprehensive junior high school chemical knowledge summary 1, basic concepts
1. Chemical change: a change that produces other substances 2. Physical change: a change that does not produce other substances 3. Physical properties: properties that do not require chemical changes (e.g., color, state, density, odor, melting point, boiling point, hardness, water solubility, etc.) 4. Chemical properties: the properties of substances shown in chemical changes (such as: flammability, combustibility, oxidation, reducibility, acid-base, stability, etc.)
5. Pure substance: composed of one substance 6. Mixture: composed of two or more pure substances, each of which retains its original properties 7. Element: A general term for a class of atoms having the same number of nuclear charges (i.e., the number of protons). 8. Atom: The smallest particle in a chemical change and cannot be divided in a chemical change
2015 college entrance Examination first round review (Supplementary content) Basic Concepts of Chemistry This chapter explains the basic concepts of chemistry are the basis of chemistry. The examination of basic concepts of chemistry in the college entrance examination involves a wide range of topics, including chemical terminology, stoichiometry and basic laws of chemistry, chemical reactions (REDOX reactions, ionic reactions), energy, dispersion system and other knowledge.
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