True.
Conductivity is the ability to transmit heat, electricity or sound. Conductivity is a physical property.
A physical property is one which can be measured or observed without changing the composition or identity of a the substance.
Conductivity is a physical property because the composition of the substance does not change.
A copper wire is still a copper wire when it is conducting electricity. Like wise, an aluminum rod is still an aluminum rod when heated. It is conducting heat but the heat does not change it, it is still an aluminum rod during the whole process.
Answer:
cross out the false piece in blue and write the true piece in red
The correct answer of this question is : Artificial luminous sources.
EXPLANATION :
As per the question, we are given some light sources like halogen, laser, sodium-vapor etc.
There are two types of bodies which are known as luminous and non luminous depending on their production of light.
All these sources given in the question are luminous sources as they have their own light. Most importantly they are not natural luminous sources like stars, firefly etc.
All these sources are artificial.
Hence, the correct answer of this question is artificial luminous sources.
Answer:
Weight is used most often for measuring solid whereas volume is used most often for measuring liquid.
Explanation:
Weight is used most often for measuring solid, because solids have definite shape. Weight is usually expressed in Newton (N) because it is a function of mass and gravity. ( weight = mass x gravity).
Whereas volume is used most often for measuring liquid, usually expressed in cubic meter (m³) because liquids have no definite shape, rather they occupy the volume of their container.