All chemical reactions involve a change in a) mass b) energy

Which of these conditions most likely produces an unstable isotope?

Which statement describes james chadwick’s discovery.

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