Mr. Avogadro started with 5.14x10^22 atoms of Pa-234. Ten days later Mr. Avogadro calculated the original sample had only 6.43 X 10^21 atoms of Pa-234. What's the half life of Pa-234? PLEASE HELP WILL MARK BRAINLIEST

Acylinder with a base diameter of x units has a volume of jxcubic units which statements about the cylinder are true? check all that apply. the radius of the cylinder is 2 x units. the radius of the cylinder is 2x units. the area of the cylinder's base is 200 square units. the area of the cylinder's base is a square units. the height of the cylinder is 2x units. the height of the cylinder is 4x units. mark this and return save and exit next submit