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.
They use to determine weather
Answer:
they will attrack
Explanation:
proton and a electron will attract each other but if there the same like electron and electron they will repel each other
Answer: Single cell organisms absorbed harmful gases from the air when they first formed
Explanation:
Answer:
A. To cause intact DNA to precipitate, so the activity of DNase can be determined.
Explanation:
The presence of DNase is special feature for some species of bacteria and can be used for identifying them. During DNase test, diluted hydrochloric acid (HCl) can be poured onto the agar plates so that there will be a clear zone close to the bacteria colonies. Each nucleotides are soluble in diluted HCl. But DNA is not soluble in the diluted HCl, thereby making the DNA to precipitate in the rest of the plate.
