Answer:
D) burning a candle
A demonstration that contains both physical and chemical changes will be BURNING OF A CANDLE.
<em>This is because when a candle is lighted up, on the top of it (where we see flame) the oxygen and other gases present around will be chemically changed (burned up)</em>
<em>When the wax in the top of the candle will get melted due to the heat of the fire a physical change takes places.</em>
1-. Because Group 7A elements have 7 electrons in their valence shell, they need 1 more electron to complete the octet. Thus, it is generally true that all Group 7 electrons have an oxidation number of 1-. This also explains why electron affinity is largely the highest for Group 7A and lowest for Group 1A.
Answer:
Thats the solution to the question
Answer:
H2Br + 2KOH ----- K2Br + 2H2O