Answer:
the reactivity of alkaline earth metals increases from top to the bottom of the group, that's because the atoms get bigger from the top to the bottom so the valence electrons are farther from the nucleus.
Number of neutrons = Atomic mass - Atomic number (number of protons)
Hope that helps!
The answer gonna be: 1/2^n = 1/2^4 = 0.0625
So, 6.25% sample has not decayed yet!!!
The answer is c it reduces the size of the force needed to carry objects into the truck
