Explanation:
Air is a combination of other gases, dust particles, pollens, spores etc. This means that air is a heterogeneous mixture where particles are unevenly distributed.
Air is not considered as a pure substance because there is not one element present in air. A substance which contains only one type of element is called a pure substance.
Therefore, it is wrong to use the term 'Pure Air' in Science.
All of the choices would be written as ionic species except C. Mg(OH)2. Mg(OH)2 is also known as <span>Magnesium hydroxide.</span>
Answer:
Decreases
Explanation:
The atmospheric pressure on the surface of the mercury pushes it up the evacuated tube until the downward pressure of the mercury equals the atmospheric pressure.
If the atmospheric pressure decreases, the mercury doesn't have to rise as high.
The mercury height decreases.
If you look at the equation for photosynthesis, it is:
<span>6CO2 + 6H2O + light energy ---> C6H12O6 + 6O2
</span>
Since CO2 (carbon dioxide) is on the left side of the equation, it is being consumed, or used up. Since O2 (oxygen) is on the right side, it is being produced.
The correct answer is the first one, "<span>Carbon dioxide is used up, and oxygen is produced."</span>
The symbol for iron is Fe. Iron is an element with an atomic number of 26 and belongs to the group of metals in the first transition series. It is the most common and known element in the Earth's crust. It is very abundant in rocky planets which includes the Earth.