During an experiment a thermometer was placed in a beaker containing hydrogen peroxide. the following observations were recorded when yeast granules were added to hydrogen peroxide. observation 1: fizzing and bubbling took place. observation 2: the temperature began to rise. based on the observation, justify the type of change (physical or chemical) that took place.

chemical change

Explanation:

A physical change is defined as a change in which a change in shape, size takes place. No new substance gets formed in these reactions. Example: Melting of ice to liquid water

A chemical change is defined as a change in which there is redistribution of atoms and chemical composition. A new substance is formed in these reactions.

Example: Oxidation of magnesium leads to formation of white magnesium oxide

When yeast is added to hydrogen peroxide, hydrogen peroxide is decomposed into oxygen and water which is a chemical reaction.

Thus as the oxygen gas is released, it leads to bubbles and the heat is released in the reaction , thus the temperature is increased.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

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