Answer:
36.55 J
Explanation:
PE = Potential energy
KE = Kinetic energy
TE = Total energy
The following data were obtained from the question:
Position >> PE >>>>> KE >>>>>> TE
1 >>>>>>>> 72.26 >> 27.74 >>>> 100
2 >>>>>>>> 63.45 >> x >>>>>>>> 100
3 >>>>>>>> 58.09 >> 41.91 >>>>> 100
The kinetic energy of the pendulum at position 2 can be obtained as follow:
From the table above, at position 2,
Potential energy (PE) = 63.45 J
Kinetic energy (KE) = unknown = x
Total energy (TE) = 100 J
TE = PE + KE
100 = 63.45 + x
Collect like terms
100 – 63.45 = x
x = 36.55 J
Thus, the kinetic energy of the pendulum at position 2 is 36.55 J.
Answer is: 0,0095 mol of hydrogen gas will be produced in reaction.
Chemical reaction: Ca + 2HCl → CaCl₂ + H₂.
m(Ca) = 0,38 g.
n(H₂) = ?
n(Ca) = m(Ca) ÷ M(Ca).
n(Ca) = 0,38 g ÷ 40 g/mol
n(Ca) = 0,0095 mol.
from reaction: n(Ca) : n(H₂) = 1 : 1.
n(H₂) = n(Ca) = 0,0095 mol.
n - amount of substance.
The question above is incomplete, the full question is given below:
What additional test would be needed to establish the exact position of hydrogen in the activity series of the following elements: magnesium, zinc, lead, copper and silver.
ANSWER
The position of hydrogen on a reactivity series can be determined by its ability to displace oxygen from the oxide of the metal concerned. If hydrogen is more reactive than a metal, it will displace oxygen from the metal oxide and reduce the metal oxide to its metal. If the metal is more reactive than hydrogen, hydrogen will not be able to reduce the metal oxide to its metal.
Chlorine will have a -1 charge and Tellurium has a -2 charge when they are ions.
Answer:
C. because the 4s orbital is at a lower energy level
