Answer:
A balance and a beaker of water!
Step-by-step explanation:
Krishne wants to measure the mass and volume of a key. The tools that are to be used are – a balance and a beaker of water.
Mass will be represent with the amount of matter that is in an object. This will be measured in terms of kilogram. The mass can easily be measured with balance.
Volume is the quantity of matter that is in the object. This is measured in terms of cubic meter. If you drop the key in a beaker of water, the water inside the beaker will increase and this increases the volume of water that will be equal to volume of key.