Option d: copper.
Because copper is an element, not a mixture.
Answer:
27) Double replacement
28) 2NaOH + H2SO4 --> Na2SO4 + 2H2O
Answer:
2n² is a formula that determines that the maximum number of electrons should be accommodated in a particular shell.
Explanation:
<span>Not all solids melt when they are heated. Some may undergo chemical changes as a result of heating. For example paper burns rather than melts</span>