Lol it literally says that he covered the distance in three seconds so I believe it would be three
Answer:
B and BBr3
Explanation:
1) 3HBr + B = BBr3 + H2 (double all equation because H2)
2) 6HBr + <em>2B </em>= <em>2BBr3</em> + 3H2
Explanation:
Because gold is a very unreactive metal and exists as a pure substance (instead of oxides).