I would say C i'm not 100% sure
Answer:
Explanation:
If an elements atomic mass and number are known you can also determine the number of protons and neutrons it has. You can also determine where it is on the periodic table. For example, if a element had a atomic mass of 10 then it would be higher up on the table then one with a mass of 20. Btw I do apex too.
Solution :-
Given :
Distance 1 = 30 km
Distance 2 = 70 km
We know that speed = distance/time
and, Average speed = total distance/total time taken
When the train acquired a speed of 30 km/hr, the time taken = 30/30 = 1 hour
Average speed = 9distance 1 + distance 2)/(time 1 + time 2)
AS time 2 or t2 is time taken for the second part of the journey of 70 km
⇒ 40 = 100/(1 + t2)
⇒ 40 + 40t2 = 100
⇒ 40t2 = 100 - 40
⇒ 40t2 = 60
⇒ t2 = 60/40
⇒ t2 = 1.5
So, t2 or time taken to travel the second part of the journey is 1.5 hours.
Speed of the second part of the journey = distance 2/time 2
⇒ 70/1.5
⇒ 46.666 km/hr or 46.7 km/hr.
Hence the answer is = 46.666 km/hr or 46.7 km/hr.
Hope it helped u if yes mark me BRAINLIEST!
Tysm!
:)
Na is in the first column on the periodic table so therefore it would have 1 valence electron
D 1
