The diagram below is a cross section of an ice-covered lake in New York State during the month of January. Points A, B, C, and D are locations at various levels in the lake. The temperature of the water at location D is 4 C.

What are the spectator ions in 2h+ + so42- + ca2+ + 2r → caso4 + 2h+ + 21?

Can someone me with questions 12 and 13 plz.

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