What is the concentration of NaCl in ppm

Skills of homo sapiens were found an excavation. the skulls were preserved because the bodies were frozen. so, these fossils are (blank) fossils. the image shows the evolution of skulls beginning 2 to 3 million years ago. based on the image, modern human skulls(blank) ape skulls.

Geothermal energy for industrial use is available almost anywhere. a. true b. false

What is the ph of a 0.0010 m hno3? 1.0 3.0 4.0 5.0