Answer:
Oxygen.
Explanation:
The copper must be combined with something in the air.
The volume of H₂ evolved at NTP=0.336 L
<h3>Further explanation</h3>
Reaction
Decomposition of NH₃
2NH₃ ⇒ N₂ + 3H₂
conservation mass : mass reactants=mass product
0.28 NH₃= 0.25 N₂ + 0.03 H₂
2 g H₂ = 22.4 L
so for 0.03 g :

In general, The more valence electrons a metal has, the stronger its metallic bonds will be because Boron is a metalloid and is ionically bonded.it is too electronegative to release its valence electrons for metallic bonding.As a result, their valence electrons feel a stronger pull from the nucleus (a greater effective nuclear charge) and are less easily released for metallic bonding.
Answer:
in nuclear fusion deep in the interiors of stars
Explanation:
Nuclear fusion -
It is the type of reaction , where two or more atomic nuclei of the atom merges together to release two or more different nuclei along with some subatomic particles , is referred to as a nuclear fusion reaction .
The reaction can very well be done on stars , because of very high energy .
Hence , a nuclear fusion occurs deep inside the stars .