Answer:
Nickel and Titanium
Explanation:
Nitinol is an alloy of Nickel and Titanium. It posesses two properties such that,
- The shape memory effect
- Super elasticity
Shape memory is the ability of nitinol to undergo deformation at one temperature, stay in its deformed shape when the external force is removed.
Superelasticity is the ability for the metal to undergo large deformations and immediately return to its undeformed shape upon removal of the external load.
Hence, the correct option is (b) "Nickel and Titanium".
Answer: Photoelectric is characterized by or involving the emission of electrons from a surface by the action of light.
Photoelectric effect is the emission of electrons when a radiation of frequency higher than the threshold frequency falls on the surface of an element. The substance which undergoes photoelectric effect is called as photoelectric.
Ground state is the state representing the lowest energy state.
Excited state is the state which represents a high energy state.
An electron in ground state absorbs energy to move to the excited state.
Permafrost soil (gelisol) is b) fragile.
I think the answer is research and development.