Answer:
Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest halogen, and is a fuming red-brown liquid at room temperature that evaporates readily to form a similarly colored gas.
<span>Gamma radiation has a shorter wavelength, a higher frequency and higher energy than radio radiation.
Wavelength is inverse to frequency and energy (i.e. higher wavelength means lower frequency and lower energy, and vice versa).</span>
Answer:
1.03 grams of hydrogen is produced from 12.5 g of Mg reacting with hydrochloric acid.
Explanation:
The balanced reaction is:
Mg+ 2 HCl → MgCl₂ + H₂
By stoichiometry of the reaction, the following amounts of moles of each compound participate in the reaction:
- Mg: 1 mole
- HCl: 2 moles
- MgCl₂: 1 mole
- H₂: 1 mole
Being the molar mass of each compound:
- Mg: 24.31 g/mole
- HCl: 36.45 g/mole
- MgCl₂: 95.21 g/mole
- H₂: 2 g/mole
By reaction stoichiometry, the following mass amounts of each compound participate in the reaction:
- Mg: 1 mole* 24.31 g/mole= 24.31 g
- HCl: 2 moles* 36.45 g/mole= 72.9 g
- MgCl₂: 1 mole* 95.21 g/mole= 95.21 g
- H₂: 1 mole* 2 g/mole= 2 g
Then you can apply the following rule of three: if by stoichiometry 24.31 grams of Mg produces 2 grams of H₂, 12.5 grams of Mg produces how much mass of H₂?

mass of H₂= 1.03 grams
<u><em>1.03 grams of hydrogen is produced from 12.5 g of Mg reacting with hydrochloric acid.</em></u>
Hey there!
B + O₂ → B₂O₃
Balance O.
2 on the left, 3 on the right. Add a coefficient of 3 in front of O₂ and a coefficient of 2 in front of B₂O₃.
B + 3O₂ → 2B₂O₃
Balance B.
1 on the left, 4 on the right. Add a coefficient of 4 in front of B.
4B + 3O₂ → 2B₂O₃
Our final balanced equation: 4B + 3O₂ → 2B₂O₃
Hope this helps!