Aflask contains 0.280 mol of liquid bromine, br2. determine the number of bromine molecules present in the flask.

              1.68 × 10²³ Molecules

Explanation:

                     As we know that 1 mole of any substance contains exactly 6.022 × 10²³ particles which is also called as Avogadro's Number. So in order to calculate the number of particles (molecules) contained by 0.280 moles of Br₂, we will use following relation,

           Moles  =  Number of Molecules ÷ 6.022 × 10²³ Molecules.mol⁻¹

Solving for Number of Molecules,

           Number of Molecules  =  Moles × 6.022 × 10²³ Molecules.mol⁻¹

Putting values,

           Number of Molecules  =  0.280 mol × 6.022 × 10²³ Molecules.mol⁻¹

           Number of Molecules  = 1.68 × 10²³ Molecules

Hence,

           There are 1.68 × 10²³ Molecules present in 0.280 moles of Br₂.

The ozone layer is a shield district of Earth's stratosphere that ingests a large portion of the Sun's bright radiation. It contains a high grouping of ozone (). It contains atoms of oxygen that keep the environment from hurtful beams that are available in the space and boundless by the sun, for instance, bright beams.  

The ozone opening is to a greater degree a downturn, less a gap in the windshield. The ozone doesn't vanish through the layer, nor is there a uniform diminishing of the ozone layer. Also, it was found in 1913 by the French physicists Charles Fabry and Henri Buisson.  

In 2017, the ozone opening arrived at a size of 7.6 million square miles (19.7 square kilometers) before beginning to recuperate. In 2016, the gap developed to 8 million square miles (20.7 square kilometers).