What is the only way to confirm a chemical change has taken place

Which feature do highland climates have that lower elevation areas do not?

Miner's coal distributors does not mine coal itself, nor does it even store or handle the coal. instead, miner's solicits orders for low sulfur coal from other firms, then purchases the required amount from suppliers and directs them to ship the coal to its customers. what is miner's

Which of these is a physical property