elements that are chemically combined. Examples of Compounds Sodium (Na) + Chlorine (Cl) NaCl Hydrogen (H) + Oxygen (O) H 2 O Carbon (C) + Oxygen (O) CO 2 •Compounds contain elements •The elements combine + lose their original properties •Compounds CAN be separated by chemical ...
atom • The smallest unit of an element that maintains the properties of the element WHAT IS A COMPOUND? Compound • A substance made of two or more different elements that are combined chemically • Properties of compounds may not be the same as properties of elements that make them up...
元素(Elements) 指自然界中一百多种基本的金属和非金属物质，它们只由一种原子组成，其原子中的每一核子具有同样数量的质子，用一般的化学方法不能使之分解，并且能构成一切物质。 化合物(pounds) 是指从化学反应之中所产生，由两种或两种以上元素构成的纯净物（区别于单质）。 例如：氯化钠(sodium chl...
Carbondioxideisasourceofplantfood.Plantshavethepowertotakethisgasfromtheair,combineitwithwater,andmakeitintotheirtissues;infact,itisfromthissourcethatallorganiccarboncomes.Mineralcompoundsaremadeofelementssuchassulphur,phosphorus,iron,potassium,sodium,andcalcium.Calciumuniteswithsulphurandoxygentoformcalciumsulphate,...
Rocks are composed of elements and compounds of elements. 岩石由一些基本元素以及这些元素的化合物所组成。 考点解析 根据朗播专家权威分析,句子“Rocks are composed of elements and compounds of elements. 英语长难句解析 ”主要针对以下知识点进行考查,关于这些知识点的讲解如下: 句子类型 简单句 英语中...
Elementsthatcomposeahumanbody WHATISANATOM?atom •Thesmallestunitofanelementthatmaintainsthepropertiesoftheelement WHATISACOMPOUND?Compound •Asubstancemadeoftwoormoredifferentelementsthatarecombinedchemically •Propertiesofcompoundsmaynotbethesameaspropertiesofelementsthatmakethemup Compounds •Substancescomposed...
4 (a)Explain why compounds of transition elements are usually coloured.[3](b)Coppe is used to make alloys such as brass. The percentage of copper in a sample of brass can be determined by dissolving the sample in concentrated nitric acid and reacting the mixture with potassium iodide. The ...
题目(a)Describe three characteristic chemical properties of transition elements that are not shown by Group ll elements. 相关知识点: 试题来源: 解析 colouredions/compoundsvariable oxidation statesformation of complexescatalytic activity 反馈 收藏
Compounds and molecules are built from elements composed of at least two atoms joined with a chemical bond. Learn how elemental personalities build compounds and molecules, explore ionic and covalent chemical bonds, and compare pure substances to mixtures. Elemental Personalities Did you know that el...
A synthetic element is a chemical element that does not occur naturally on the earth. These are prepared byartificiallyandare unstable. The first synthetic element made was Technetium. Compounds Compounds contain more than one kind of atoms (more on atoms, later). It cannot be separated into co...