I'm not that smart :) When a child slides down a slide (if there is no friction and all of the mechanical energy is conserved) what would happen?

Question 3 options:

A. Potential energy would turn to Kinetic energy

B. The energy is destroyed

C. Kinetic energy would turn in to Potential energy

D. All energy stays the same

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.

Anthracite is so hard and pure it is also referred to as a renewable resource metamorphic rock hot bituminous coal dirty fuel