Answer:
Option A.
2Na + 2H2O —> 2NaOH + H2
Explanation:
To know which option is correct, we shall do a head count of the number of atoms present on both side to see which of them is balanced. This is illustrated below below:
For Option A:
2Na + 2H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
4 H >>>>>>>>>>>> 4 H
2 O >>>>>>>>>>>> 2 O
Thus, the above equation is balanced.
For Option B:
2Na + 2H2O —> NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 3 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
For Option C:
2Na + H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
2 H >>>>>>>>>>>> 4 H
1 O >>>>>>>>>>>> 2 O
Thus, the above equation is not balanced.
For Option D:
Na + 2H2O —> NaOH + 2H2
Reactant >>>>>>> Product
1 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 5 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
From the illustrations made above, only option A is balanced.
Out of the five major mass extinction, one is Cretaceous-Tertiary extinction (K-T extinction). It happened 66 million years ago marked by the end of the Cretinous period.
Answer:
The structure that is located between the auricle and the eardrum is the ear canal.
Explanation:
The ear canal, or external ear canal, is a a tubular hole about 30 mm long that runs from the auricle to the eardrum, forming part of the external ear.
Its function is to conduct sound, in the form of vibrations, from the outside to the eardrum. It also has the function of producing a viscous secretion called cerumen, capable of trapping dust particles and small foreign bodies.
Other options are not correct because:
- <em>Stirrup is located in the middle ear, along with the anvil and hammer.
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- <em>Cochlea is in the inner ear and continues with the auditory nerve.</em>
