Why can't you balance a chemical equation by changing the subscript?

During chemistry class, carl performed several lab tests on two white solids. the results of three tests are seen in the data table. based on this data, carl has concluded that substance b must have bonds.

Aroller coaster car is traveling down a track at 22 m/s. the car has a mass of 2000 kg. what is the kinetic energy of the car? a) 22,000 j b) 968,000 j c) 484,000 j d) 44,000 j

Apiece of metal with a length of 1.42 cm was measured using four different instruments. which of the following measurements is the most accurate?