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Fill in the Blank: the Basic Conditions Necessary for a Chemical Reaction is _______ - Chemistry

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Question

Fill in the blank:

The basic conditions necessary for a chemical reaction is _______

Fill in the Blanks

Solution

The basic conditions necessary for a chemical reaction is close contact .

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Chapter 5: Language of Chemistry - Objective type questions

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Selina Concise Chemistry [English] Class 7 ICSE
Chapter 5 Language of Chemistry
Objective type questions | Q 1.4

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