Answer:
When the cell excretes sodium from within against the natural tendency of matter it is performing active transport.
Answer:
Each tool is precisely designed for a specific purpose, so choosing the correct tool will also decrease the amount of effort required to get a job done right without causing damage to either the equipment or the surface
Not a physical change, It's a chemical change because you can't change the process back to its original state. If it was a physical change, you could change it back to its original state using the boiling, evaporating or melting process.