All of the above are chemical reactions.
If that is a choice
Answer: Yes, Natural selection is natures way of making the fittest and top dogs of the food chain, It can produce a change in individuals and populations by completely reducing or wiping out a population not fit for survival in its inviroment and can even force a change of the creature to make it able to survive.
Example: would be rabbits, a snow rabbit wouldn't survive very well in the desert and a jack rabbit wouldn't be able to survive in the cold winter due to temp and the fact that predators like wolves would be able to spot it easier from its color of its fur.
Note: Hope this helps, and I hope this is want it was asking. Good luck :)
The correct question is as follows: 0.500 moles of potassium oxide is dissolved in enough water to make 2.00 L of solution. Calculate the molarity of this solution (plz help!)
Answer: The molarity of this solution is 0.25 M.
Explanation:
Molarity is the number of moles of a substance divided by volume in liter.
As it is given that there are 0.5 moles of potassium oxide in 2.00 L of water so, the molarity of this solution is calculated as follows.

Thus, we can conclude that molarity of this solution is 0.25 M.
4.95 is the number of molecules in 500m cube of Oxygen at room temperature and pressure
we have got data
pressure=1atm
temperature=298 k
volume=500 m^3
gas constant, R=8.31
now, by applying ideal gas equation
PV=nRT
1×500=n×8.31×298
n=2476.38/500
n=4.95
It is the lowest part of the material and has chemical elemental properties. Atoms do not independently exist; rather, they combine to form ions and molecules, which then combine to form the material that we can see, feel, and touch.
Molecules are made up of one or more atoms connected by covalent (chemical) connections. Atoms can be visualized as circles with a nucleus in the center (made up of protons and neutrons) and one or more concentric circles around it that indicate the "shells" or "levels" in which the electrons surrounding the atom's nucleus are located, as well as markings that identify the electron. each level
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