1- change of state (boiling)
2-increase in acidity
3-methylxanthines (caffeine) theobromine and theophylline
4- lemon juice
If the states of matter have changed such as from solid to liquid, you have to remove or add energy.
Answer is d. in hetrogeneous you can separate things from each other
<span>Ethylpropylamine has a chemical formula of C2H13N. It has a molecular weight of 83.166 g/mol. It's considered highly flammable and dangerous if swallowed. It should not come in contact with skin or in eyes and it should not be inhaled.</span>
