C. It has mass and volume
Explanation:
Every atom of an element has mass and volume. Mass is the amount of substance it contains this is usually a function of their subatomic particles.
The bulk of the mass of an atom is concentrated in the nucleus where we have protons and neutrons. Electrons do not really add much to the mass of an atom.
Atoms also have specific volume.
- The reason for our selection is that atoms are the smallest particle of matter.
- Matter is anything that has weight and occupies space.
- Since it is matter, it must have specific weight and volume
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Answer: 6.38 moles of
are needed to react with 2.55 mol of 
Explanation:
The balanced chemical reaction for the combustion of ethyne is:

According to stoichiometry:
2 moles of
require = 5 moles of 
Thus 2.55 mol of
require =
moles of 
Thus 6.38 moles of
are needed to react with 2.55 mol of 
Answer:
15 grams of water
Explanation:
15 grams of water of water would lose heat the faster compared to higher masses of water.
Water generally is a poor conductor heat.
- To heat up a unit of water, significant amount of energy must be added to the body of water.
- With time, the body continues to increase in temperature.
- A 500g mass of water will take more time to lose heat.
Answer:
27 min
Explanation:
The kinetics of an enzyme-catalyzed reaction can be determined by the equation of Michaelis-Menten:
![v = \frac{vmax[S]}{Km + [S]}](https://tex.z-dn.net/?f=v%20%3D%20%5Cfrac%7Bvmax%5BS%5D%7D%7BKm%20%2B%20%5BS%5D%7D)
Where v is the velocity in the equilibrium, vmax is the maximum velocity of the reaction (which is directed proportionally of the amount of the enzyme), Km is the equilibrium constant and [S] is the concentration of the substrate.
So, initially, the velocity of the formation of the substrate is 12μmol/9min = 1.33 μmol/min
If Km is a thousand times smaller then [S], then
v = vmax[S]/[S]
v = vmax
vmax = 1.33 μmol/min
For the new experiment, with one-third of the enzyme, the maximum velocity must be one third too, so:
vmax = 1.33/3 = 0.443 μmol/min
Km will still be much smaller then [S], so
v = vmax
v = 0.443 μmol/min
For 12 μmol formed:
0.443 = 12/t
t = 12/0.443
t = 27 min