Answer: The atomic mass of a Europium atom is 151.96445 amu.
From the given information:
Percent intensity is 91.61% of Europium atom of molecular weight 150.91986 amu.
Percent intensity is 100.00% of Europium atom of molecular weight 152.92138 amu.
Abundance of Eu-151 atom:

Abundance of Eu-153 atom:

Atomic mass of Europium atom:

Therefore, the atomic mass of a Europium atom is 151.96445 amu.
The answer is "156.6 m/s".
This is how we calculate this;
-N + mg = ma = mv²/r
For "weightlessness" N = 0, so
0 = mg - mv²/r
g - v²/r = 0
v =√( gr)
g = 9.8 and r = 2.5km = 2500 m
v = √(9.8 x 2500)
= 156.6 m/s
Protons have a positive charge which is indicated by a + sign.
Hence, the answer is C.
50 +50 =100 Since it’s sitting on a 50m cliff that’s high with a mass of 50 kg it would be adding because once it goes down it’s adding speed
Regardless of what direction an object is moving, the acceleration
due to gravity is always directed toward the center of the Earth.
That's the direction commonly known as "down".