Ozone Layer is important .
because it protects us from harmful radiations coming from the sun .
Atmosphere is Important .
-it protects us from harmful radiations coming from the sun .
-it adjusts the temperature of the earth .
iron Nails Rust.
because it is combined with Oxygen in the presence of moisture (water) .
Bridges pillars painted with isolated material .
to protect them from iron rusting .
Adding Yeast to Dough .
because yeast produces Co2 during fermentation which expands by heat to make the bread tasty.
Oxy Acetylene flame is used in cutting and welding metals .
because its temperature reaches about 3500 which is suitable to cut and weld metals.
Oxygen percentage is stable although it is consumed in respiration.
because the consumed O2 is compensated by green plants during photosynthesis process.
the increase of CO2 percentage is harmful.
because it leads to suffocation of living organisms.
