Answer:
This is a cycle of reactions, because you start and end with the same substance, copper metal. In the first reaction, copper metal is oxidized by nitric acid to form copper (II) nitrate, Cu(NO3)2. ... Finally, the copper ions in the copper sulfate are reduced to copper metal by magnesium.
Biogas is a renewable, as well as a clean, source of energy. Biogas plants significantly curb the greenhouse effect: the plants lower methane emissions by capturing this harmful gas and using it as fuel. Biogas generation helps cut reliance on the use of fossil fuels, such as oil and coal.
Answer:Some individuals may be natural good at maths or may be just smart kids who are good with mathematics
Explanation:Some students may be intelligent or good at maths which means the shoe size will not be the cause of their quantification skills.
A confounding variable refers to another variable that you may have not take notice of but which is very likely to act on the variable you are trying to measure and make that change you are looking for , its an extra variable. It can mess up your experiment and give you result that are not caused by what your projected. They can assume a correlation that doesn't exist and insert bias in your study. For this reason you have to know these variable before you start your research or study in order to avoid them.