The right option is; c. can be used and consumed without risk
The defining characteristic of potable water is that it can be used and consumed without risk.
Potable water is the water that is considered safe for human consumption without risk of health problems. Potable water meets drinking water quality standards in terms of physical, chemical and microbiological parameters. Potable water has been treated and it is assumed to be considerately free of harmful pathogens such as bacteria and contaminants.
Scientists publish their results and conclusions in scientific journals.
In this question in which is the major source then of free oxygen in the earth's Proterozoic atmosphere is being produce by the evaporation of the ocean water. Hope this answer would be of big help to this assignment then.
Answer:
a glass of muddy water
Explanation:
Pure substances contain only one element or compound.
Calcium is one element so it is a pure substance. Ice and water have the same molecular structure, so it is a pure substance. Aluminum oxide is a chemically pure compound.
The only example that is not a pure substance is muddy water due to the multiple components of mud mixing with the components of water.
Hope that helps.