<span>HBr is covalent bond.!
</span>Hydrogen and Bromine will share their electrons, to obtain the electron configuration of a noble gas<span>.
</span>
hope this helps!
Mass of H₂O₂ = 88.778 g
<h3>Further explanation</h3>
The mole itself is the number of particles contained in a substance amounting to 6.02.10²³
Mole can also be determined if the amount of substance mass and its molar mass is known

moles of H₂O₂ = 2.61
So the mass of H₂O₂(MW=34,0147 g/mol) :

Say that you have 100³
instead of writing and solving 100x100x100 three times to solve it, you can just write 100³
the exponents in scientific notation make the whole process easier.