Did barium chloride and barium sulfate produce similar colored flames? yes, both compounds produced pale yellow-green flames. no, barium chloride produced pale yellow-green flames and barium sulfate produced red flames. no, barium chloride produced purple flames and barium sulfate produced yellow flames. yes, both compounds produced red flames.

Answer = A

Explanation:
                     When Ba⁺² is subjected to flame it burns yellow-green under the flame. This colour is generated due to the fact that on exposure to heat the electrons of metal absorbs energy and gets excited to higher energy level, and bounce back to ground state with the elimination of energy absorbed. This energy of particular wavelength falls in visible region and gives yellow-green colour. When compounds of Barium chloride and Barium Sulphate are subjected to flame the give same colour. (Reference for BaSO₄ = https://carnicominstitute.org/wp/barium-tests-are-positive/)

High-energy and unstable.

Answerstudying coal cumbustion as an energy source;