The cell membrane has a protective barrier around the cell, and also regulates which substances or materials go inside and out.
Answer:
Oxygen
Explanation:
If two balloons are filled with hydrogen gas and helium gas respectively, then we want to identify what gas is in each balloon, we have to do so by exposing the both balloons to flame in an oxygen atmosphere.
Hydrogen combines with oxygen in the presence of a flame with quite a loud sound and the flame is sustained but when a flame is brought near helium gas in a balloon, the gas will only make a little sound when exposed to the flame and extinguish the flame.
The reason for the explosion of the gas in the hydrogen balloon is that combustion of hydrogen gas is exothermic. The heating up of surrounding air molecules leads to a sudden explosion.
However, the helium balloon makes a little sound when the balloon is ruptured releasing helium gas which extinguishes the flame.
Answer: If you mean N2 and not Nz, it should be C.
Explanation:
The given blank can be filled with less and even cooler.
A long duration of decline in the temperature of the surface of the Earth and atmosphere, leading to the expansion or existence of the polar and continental ice sheets and alpine glaciers is known as an ice age.
During an ice age, there are many periods of glaciation that are periods when ice sheets and glaciers cover the majority of the Earth's surface.
The ice reflects more sunlight back into outer space than does the vegetated or bare ground. As the glaciers and ice sheets are more reflective, they captivate less sunlight and thus discharge less heat. This makes the climate of the Earth to become even cooler during the times of glaciation.