Many people believe that the atomic number of the atom is the number of electrons in the atom. Describe when this is the case
2 answers:
Answer: The atomic number of the atom is the number of electrons in the atom only when the atom is neutral.
Explanation: For a neutral atom, the number of positive charges is equal to the number of negative charges and thus the atomic number is equal to the number of electrons or the number of protons.
But for a positive and a negative ion, the electrons are lost and gained respectively by that element and thus the number of electrons are not equal to the number of protons. Now atomic number is equal to the number of protons only. The number of electrons = number of protons - charge.
Example: For sodium , the atomic number is 11 and it has 11 electrons.
For sodium ion , the atomic number is 11 but the number of electrons = (11-1) = 10.
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Answer:
a) The student must run flight of stairs to lose 1.00 kg of fat 709.5 times.
b) Average power
P(w)= 1062.07 [w]
P(hp)=1.42 [hp]
c) This activity is highly unpractical, because the high amount of repetitions he has to due in order to lose, just 1 Kg of fat.
Explanation:
First, lets consider the required amount of work to move the mass of the student. (considering running stairs just as a vertical movement)
Work:
Where m is the mass of the student, g is gravity (9.8 m/s) and d is the total distance going up the stairs (0.15m *85steps= 12.75m )
Converting from Joules to Kcals:
Now lets take into account the efficiency of the human body (20%)
2.537 ---> 20%
x ---> 100%
So the student is consuming 12.685 KCals each time he runs up the stairs.
Now,
1 g --> 9 Kcals
1000 g --> 9000KCals
Burning 1 g of fat, requieres 9 KCals, 1000g burns 9000KCals. So in order to burn a 1Kg of fat:
He must run up the stairs 709.5 times, to burn 1 Kg of fat.
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For b) just converting units, taking into account the time lapse. (53103.75 is the 100% of the energy in joules, from converting 12.685Kcals to joules)
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Answer:
The chemical formula for the molecule is
Explanation :
Molecular formula : It is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Structural formula : It is a formula in which the lines are used between the bonded atoms and the atoms are also shown in the structural formula.
In the structural formula, the lines are used between the atoms.
As per given information of compound we conclude that, there are 4 carbon atoms, 9 hydrogen atoms and 2 oxygen atoms.
Thus, the chemical formula for the given molecule will be,
