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Reactivity series of metals

Reactivity series When metals react with other substances the metal atoms form positive ions by loosing electrons (from their outermost shells). However, some metals tend to form ions more easily than others. This tendency of forming positive ions (by loosing electrons) is called reactivity. Metals can be arranged in a list in order of their reactivity , and such a list is called reactivity series . In a reactivity series , the most reactive element is, usually, placed at the top and the least reactive element at the bottom . The metals potassium, sodium, lithium, calcium, magnesium, aluminium, zinc, iron, tin, lead, copper, silver and gold can be arranged in the order of their reactivity from their reactions with water and dilute acids . The non-metals hydrogen and carbon are often included in the reactivity series as they are useful in extracting metals from their oxides (met
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Acids, alkalis and salts

In this chapter you will learn: Acids and alkalis Reactions of acids What is neutralisation reactions? Strong and weak acids pH of acids and alkalies Neutralisation of acids and salt production Acids and alkalis An acid is a substance that produces Hydrogen ions (H+) in water. Acid Turns blue litmus paper red . Acidic solutions have pH values less than 7 . These are 7 strong acids: chloric acid, hydrobromic acid, hydrochloric acid, hydroiodic acid, nitric acid, perchloric acid, and sulfuric acid. Strong acids completely dissociate into ions , in water. Weak acids only partially dissociate. The pH scale is used to measure a solution is acidic , neutral , or alkalinie .
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What are direct And indirect speech

What is Direct Speech?: Definition: When we repeat the actual words of the speaker, it is called direct speech . We use quotation marks or inverted commas . Examples: He said, "I am busy ." What is Indirect Speech?: Definition: When we do not repeat the speaker's actual words , it is called indirect or reported speech . We use our own words , without changing their meaning. We do not use quotation marks here. Examples: He said that he was happy . Reporting Verb: These are verbs which are used for citing or reporting another speaker's ideas . These can be used both in quoting or paraphrasing . Most commonly used reporting verbs are say and tell . For example: ( He said, She said, ) How to change direct speech in to indirect speech: 1. The word "that" is used as a conjunction between the reporting verb and the reported speech. 2. If the reporting verb is in present tense or future ten
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30 Imperative sentence examples

What are Imperative Sentences? Imperative sentence definition: In English, sentences can be of different types, and hence can be classified in different ways. One way to classify them is by their function. With this in mind, sentences can be classified as declarative , imperative , interrogative , and exclamatory sentences. In this article we focus on imperative sentences. Imperative sentences are used: to give an order or a command to make a request to give instructions to offer advice , a suggestion or an invitation In an imperative sentence, the verb typically comes at the beginning, and the subject is altogether missing. More specifically, the subject is implied and often refers to the second-person, or "the reader". An imperative sentence ends with a period (.) or an exclamation mark (!) depending on the forcefulness of the command. Also,
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What are Adverbs?

Adverbs, different types of adverbs and their examples: What Are Adverbs? Definition: An adverb is a single word , or a group of words , that modifies a verb , an adjective or another adverb. An adverb tells us when , where , how and in what manner an action is performed. Let's consider the following examples: James was sleeping peacefully . Sam walks gracefully . He is an extremely talented singer. Nina plays really confidently. Here the adverb "really" modifies the adverb "confidently" . Note: Many adverbs end in "ly" , but this is not always true. For example: ( fast, never, well, very, least, more, less, now, there ) Also, there are words, like "friendly" and "lovely" , that end in "ly" , but they are adjectives , not adverbs . Types of adverbs: 1. Adverb Of Time: An adverb of time tells us when something is done. T
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Auxiliary Or Helping Verbs

What are Auxiliary Or Helping Verbs? A verb of this type helps the main verb in a sentence. It comes before the main verb in a sentence. A helping verb has no meaning on its own. Auxiliary verb is used forming the tense, moods and voices. The following are some examples of helping verbs: is , am , are , was , were , will , has , have . There is another kind of auxiliary verb called a modal verb. The modal verbs are can, could, may, might, must, ought to, shall, should, will, and would. The modal auxiliary verbs never change their forms. Maria is eating a chocolate. She will meet her sister tomorrow. He does not like juice. They have gone to the party. Has she just meet her father? She has just gone. He has just finished his homework. I am eating. They are playing. He is reading a story. They were watching t.v. He
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9 types of Pronouns with examples

What are Pronouns? Definition: A pronoun is a word that is used in place of a noun. Therefore, they act as substitutes for the nouns that they replace. Pronouns save you from having to repeat a noun over and over again. Some of the most common pronouns are: he, she, they, you, it, and we. It is important to note that because pronouns replace nouns, they are used the same way the nouns are used in a sentence. You would use them as subjects or objects in a sentence. Before we move forward, following is a graphics showing relationship between nouns , pronouns and adjectives . Nouns, Pronouns and Adjectives Let's consider the following examples: 1. Sam is a good singer. He is good with drums. Here, in the second sentence we have replaced the noun , Sam , with the pronoun , he . 2. John and Paul are going for a picnic tomorrow. They will leave early in the morning
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