Burning a magnesium ribbon in the air is an addition reaction while heating potassium manganate 7 is a decomposition reaction.
<h3>Addition and decomposition reactions</h3>
Magnesium burns in air to produce magnesium oxide as follows:

Potassium manganate 7 burns to produce multiple products as follows:

Thus, the MgO will be heavier than Mg. On the other hand,
will be less heavy than
.
More on reactions can be found here: brainly.com/question/17434463
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Answer:
FALSE!!! Thermal energy can be transformed to heat.
Explanation:
=<span><span><span><span><span><span><span><span><span>148.413159d</span><span>f2</span></span>i</span>l</span><span>o4</span></span>s</span>y</span>+<span><span>a<span>l2</span></span><span>o3</span></span></span>+<span>a<span>l is the answer and have a nice day :)</span></span></span>
Answer:
Sr is the more metallic element
Bi is the more metallic element
O is the more metallic element
As is the more metallic element
Explanation:
One thing should be clear; metallic character increases down the group but decreases across the period.
Hence, as we move across the period, elements become less metallic. As we move down the group elements become more metallic.
This is the basis upon which decisions were made about the metallic character of each of the elements listed above.
The choices for this are as follows:
A) gases; solids
B) metals; nonmetals
C) nonmetals; metals
<span>D) reactive; nonreactive
</span>
I think the correct answer is option B. The stair-step line between the pink squares and the yellow squares separates the metals from the nonmetals. Hope this helps.