Answer:
Step-by-step explanation:
Cake: Its a mixture. Reason : Cake contain various ingredient which can act as compound alone and on mixing these compound properties of each compound remain the same even after the formation of cake.
Iron : Iron has four naturally-occurring stable isotopes, 54Fe, 56Fe, 57Fe and 58Fe
Hydrogen : The hydrogen atom is the simplest of all atoms: it consists of a single proton and a single electron. In addition to the most common form of the hydrogen atom that is called protium, two other isotopes of hydrogen exist: deuterium and tritium.
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