For the very last question you would first divide 8,900 by 12 and the number you get will be the answer. You should get 741.66
Answer:
1.
2.
Explanation:
1.Momentum is given as the product of mass by velocity of an object.
Momentum,
m=1,500kh, v=6m/s

2.Momentum,
m=7800kg, v=30m/s

new mass=7800+800=8600
As mass is increased, so does the resultant velocity as mass is directly proportional to velocity.

While staying in the same period, if we move from left to right across the period, the atomic radius decreases. The reason is, in a period the number of shells remain the same and the number of electrons and protons increase as we move across the period to the right. The increased electrons and protons attract each other with greater force and hence the atomic size decreases.
So the element on the left most will have the largest atomic radius. So the correct ans is Potassium. Potassium will have the largest atomic size among Potassium, Calcium and Scandium.
Q = m x c x ΔT
2500 = 0.135 x C x 80.5
2500 = 10.8765 x C
C = 230.043 J/Kg.K
hope this helps