Answer:
• One mole of oxygen is equivalent to 16 grams.
→ But at STP, 22.4 dm³ are occupied by 1 mole.
Answer:Chemistry is important for meeting our needs of food,clothing,shelter,health,energy,and clan air,water,and soil.
<h2>Answer:</h2>
The density of mercury molecule is higher than water.
<h3>Explanation:</h3>
Density is defined as mass per unit volume.In other words, density is the amount of matter within a given amount of space. water has the density of 1.0 gram per milliliter whereas the mercury has a density of 13.6 grams per centimeter squared.
One reason for the differences in density between mercury and water is that the atomic mass of mercury is 200.59 grams per mole. The atomic mass of water is 18.0 grams per mole. This is because mercury has a larger nucleus than hydrogen or water.
Additionally, there are strong inter-molecular forces (hydrogen bonds) between water molecules. hydrogen molecules do not stack upon one another as nicely as mercury atoms. Thus, there is additional empty spaces between the water molecules leading to its lower mass per volume(density)
I think it is enzymes.Inside our body most of the chemical reactions are speeds up by enzymes.These enzymes decreases the minimum energy that is required for the reaction to happen. ;-]. Actually it works like a catalyst.
Answer: 
Explanation:-
Single replacement reaction is a chemical reaction in which more reactive element displaces the less reactive element from its salt solution.
As zinc is more reactive than copper, it could easily displace copper from its aqueous solution and thus leads to formation of zinc (II) sulfate and pure copper.
The chemical reaction can be represented as :
The phases are represented as (s) for solid sate, (l) for liquid state, (g) for gaseous state and (aq) for aqueous state.
