In which compound does hydrogen have an oxidation number of -1

What is the approximate vapor pressure when the gas condenses at 70 degrees celsius

Rays from the sun are not considered matter true or false

How can you write e method for the experiment of separating sand from water by filtration process? 1-materials 2-steps 3-conclusion also the same for the separating process of water and salt by filtration or distillation. quick because i need to finish my hw