Answer:
D. A brown gas produced
Explanation:
When a chemical reaction occur, there are several changes that takes place such as change in color, odor change, formation of a gas, and formation of a precipitate etcetera.
In the given chemical reaction, two colorless gas (NO and O2) react together and form brown gas (NO2). So, the change of gas from colorless to brown gas is the evidence that shows chemical reaction occurred.
Hence, the correct option is "D. A brown gas produced".
The answer to this question would be: The soil
So here are the answers that will complete the given statements above.
11. All of the planets in the solar system have MOONS or NATURAL SATELLITES <span>with the exception of Mercury and Venus.
12. </span>Because there is no ATMOSPHERE <span>on the moon, any liquid water would have evaporated into space long ago.
13. </span><span>The length of a planet’s day is determined by its SPEED OF ROTATION.
14. </span><span>The large, irregular objects mostly located between Mars and Jupiter are ASTEROIDS. Or in general term, it is known as the asteroid belt.
15. </span><span>Icy objects that mostly travel in long, elliptical orbits around the sun are COMETS.
Hope these answers help.</span>
Answer:
Due to no resistance.
Explanation:
Most mosquitoes perish when DDT chemical was sprayed the first time because these mosquitoes are vulnerable to the DDT chemical and there is no resistance present in their body against this chemical. DDT chemical is an insecticide which is used against insects or pests that causes damage to human, organisms and crops. DDT was first synthesized in 1874 by the Austrian chemist named Othmar Zeidler.
