All types of scientific investigations include making

All types of scientific investigations include making hypothesis.

Explanation:

Scientific investigations refer to science research and consequential formulation of hypothesis based on pieces of evidence. These pieces of evidence are later analysed and carefully examined to support the hypothesis.

Hypothesis in itself means an assumption or an explanation that is proposed at the starting of an experiment. The crux of the scientific investigation is validating the hypothesis based on hard proofs. Besides hypothesis making, there are parts of scientific investigation which includes observation, analysis, measurement and experimentation.

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

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it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.