The answer to your question is option 1. I hope this has helped.
B is the right answer because it’s a double replacement reaction and the potassium is balanced with the sulphate
Explanation:
Given that:
Distance traveled = 3150m
Average speed = 350m/min
Suggested speed = 375m/min
Unknown:
Time = ?
Solution:
Speed is the rate of change of distance with time.
it is mathematically expressed as;
speed = 
Initial time using speed 350m/min can be calculated by making time the subject of the formula;
time taken = 
time taken at speed of speed of 350m/min =
= 9min
to seconds = 9 x 60 = 540 seconds
time taken at speed of 375m/min =
= 8.4min
to seconds = 8.4 x 60 = 504 seconds.
It could have taken 504 seconds sooner saving 36 seconds.
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Speed brainly.com/question/10177389
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Ans: Elements in the same period have the same number of electron shells.
Answer : The current passing between the electrodes is, 
Explanation :
First we have to calculate the charge of sodium ion.

where,
q = charge of sodium ion
n = number of sodium ion = 
e = charge on electron = 
Now put all the given values in the above formula, we get:

Now we have to calculate the charge of chlorine ion.

where,
q' = charge of chlorine ion
n = number of chlorine ion = 
e = charge on electron = 
Now put all the given values in the above formula, we get:

Now we have to calculate the current passing between the electrodes.



Thus, the current passing between the electrodes is, 