Answer:
Energy consumed by the electric kettle in 9.5 min =Pt=(2.5×10
3
)×(9.5×60)=14.25×10
5
J
Energy usefully consumed =msΔT=3×(4.2×10
3
)×(100−15)=10.71×10
5
where s=4.2J/g
o
C= specific heat of water and boiling point temp=100
o
C
Heat lost =14.25×10
5
−10.71×10
5
=3.54×10
5
To be sure that the color is due to sodium, do a
flame test. This is used to identify the presence of small number of metal ions
in a compound. For sodium, the brilliant color of bright yellow is a result of
an excited electron in a very high level of energy and fall to a lower level called
the ground state.
In
addition, metals have different jump sizes in the energy level and
this means that each different metal will have a different pattern of spectral
lines, which results to different flame color.
Answer:
B
Explanation:
B. Women have straighter teeth.
Answer:
* First fight the reaction time of the person, which is approximately 1/10 s, remember that the stopwatch does not stop alone
* Problems to synchronize when starting to measure the oscillation and end point of the oscilloscope, this error needs a good control system to be decreased.
*Effect of friction with air
Explanation:
In the measurements of the oscillatory movement in general, the most difficult magnitude of the measurement is the period, by reasoning
* First fight the reaction time of the person, which is approximately 1/10 s, remember that the stopwatch does not stop alone
* Problems to synchronize when starting to measure the oscillation and end point of the oscilloscope, this error needs a good control system to be decreased.
* Effect of friction with air
