都是些基础类的东西...没事做...发发看..Chemistry is the study of matter, its properties, and its changes or transformations.Matter is anything that has mass and takes up space.State of matter: solid, liquid, or gas.Physical property : One is the state of matter at room temperature. Other physical properties include colour, odour, lustre, solubility, and melting and boiling points.Chemical property : determine the changes or transformations that substances may undergo.Pure substance is one in which all the particles that make up the substance are the same.Elements are pure substances that cannot be broken down into simpler substances.Compounds are pure substances that contain two or more different elements in a fixed proportion.A physical property is a characteristic of a substance.A change (such as dissolving or melting) in the size or form of a substance, which does not change the chemical properties of the substance, is called a physical change.A chemical property is a characteristic behaviour that occurs when a substance changes to a new substance. The change itself is called a chemical change.The starting materials in such a change are called reactants, and the new materials produced are called products.Chemists can use chemical tests, or distinctive chemical reactions, to identify unknown gases or other substances.Active ingredients, chemical symbol, dioxide, carbonate, monoxide, chloride, homogeneous mixturesMatter contains pure substances and mixtures.Pure substances contain compounds and elements.Mixtures contain solutions and heterogeneous mixtures.Acid: a substance that tastes sour, turns blue litmus paper red, reacts with some metals to produce hydrogen gas, is a good conductor of electrify in solution, and reacts with a base to produce a salt and water.Acidic oxide: a nonmetal oxide that reacts in water to form an acid.Antacid: a mild base that can neutralize acid.Antioxidant: a substance that acts as a preservative by slowing down the rate of oxidation of molecules in food, particularly fats.Base : a substance that tastes bitter, feels slippery, turns red litmus paper blue, is a good conductor of electricity in solution, and reacts with an acid to produce a salt and water.Basic oxide: a metal oxide that reacts in water to form a base.Catalyst: a substance that increases the rate of a chemical reaction without being consumed by the reaction.Chemical equation: a written representation of a chemical reaction using chemical formulas for reactants and products.Combination reaction: the combination of smaller atoms and/or molecules into larger molecules; also called a synthesis reaction.Combining capacity: the number of electrons an atom can gain, lose, or share to form an ionic compound (or a stable molecule).Combustion: the chemical reaction that occurs when a substance reacts very quickly with oxygen to release energy.Decomposition reaction: a chemical reaction in which a compound is broken sown into elements or smaller compounds.

Concentrated solution: a solution that contains a large amount of solute compared to solvent.Dilute solution: a solution that contains a small amount of solute compared to solvent.Double displacement reaction: a chemical reaction that occurs when elements in different compounds displace each other or exchange places to form two new compounds.Electrolyte: a substance that can conduct electricity when it dissolves in water.Endothermic: a chemical reaction that absorbs heat (energy) from the surroundings.Exothermic: a chemical reaction that releases heat (energy) to the surroundings.Alkali metals: elements in the far left column of the periodic table; also called Group 1 elements.Alkaline: a substance that may also be described as basic.Alkaline earth metals: elements in the second column from the left of the periodic table; also called Group 2 elements.Halogens: elements in the second column from the right of the periodic table; also called Group 17 elements.Hydrate: a solid compound that contains water molecules as part of the solid crystalline structure.Hydrocarbon: a compound composed of hydrogen and carbon.Incomplete combustion: the chemical reaction that occurs when there is not enough oxygen available for complete combustion; the incomplete combustion of a hydrocarbon produces carbon monoxide, carbon, carbon dioxide, and water.Indicator: a substance that turns a different colour in acids and bases.Inhibitor: an antioxidant that slows down chemical reactions; used as a preservative in food.Inorganic: compounds that do not contain a combination of carbon and hydrogen atoms; carbon dioxide, water, and ammonia are all inorganic.Law of Conservation of Mass: a scientific law that states that the total mass of the reactants in a chemical reaction is always equal to the total mass of the products.Molecular compound: a compound formed by the combination of two or more atoms held together with covalent bonds.Neutralization: a chemical reaction between an acid and a base that produces a salt and water.Noble gases: the elements in the far right column of the periodic table; also known as Group 18 elements.Organic」: compounds that contain atoms of both carbon the hydrogen; many organic compounds also contain oxygen and nitrogen atoms; sugars, fats, and proteins are all organic.Oxyacid: a compound formed when hydrogen combines with a polyatomic ion that contains oxygen.Ozone: a gas that consists of three oxygen atoms.pH scale: a numerical scale, ranging from 0 to 14, used to measure how acidic or basic a solution is.Precipitate: a solid formed from two solutions.Rate of reaction: the speed at which a reaction occurs.Salt : a combination of positive and negative ions; formed by the reaction of an acid and a base.Saturation: when a substance reaches saturation, this means that, at a particular temperature, the substance is holding the maximum amount of water vapour or a martial possible.Single displacement reaction: a chemical reaction in which one element displaces, or replaces, another element in a compound.Skeleton equation : a representation of a chemical reaction in which the formulas of the reactants are connected to the formulas of the products by an arrow.Universal indicator: a substance that turns different colours in solutions with different pH values.Word equation : a representation of a chemical reaction.pH is stand for "power of Hydrogen"the word equation of Photosynthesis:Carbon Dioxide + Water + light = oxygen + glucose

ll我爱你！！！
很有用
啊这
些
加拿大science上的我要死了