I believe you may be referring to cold welding? This is when two pieces of metal are put together in a vacuum and are thus permanently "cold-welded" together
Friction is not useful in Machinery sometimes, Since it leads to the wear and tear of machine parts.
Answer:
See Explanation
Explanation:
A substitution reaction means the replacement of one or more hydrogen atoms in an alkane by another atom or group. It does not introduce a double bond into the product. The product retains single bonds between the species present.
For instance;
CH4 + Cl2 -------> CH3Cl +HCl
is a substitution reaction
Dehydrogenation is the process of removing two hydrogen atoms from a saturated compound compound thereby yielding an unsaturated product.
E.g
C2H6 --------->C2H4 + H2
The key difference is that substitution reaction yields a saturated product while dehydrogenation yields an unsaturated product.
Answer is: ammonia experience only dispersion intermolecular forces with BF₃ (boron trifluoride) because BF₃ is only nonpolar molecule (vectors of dipole moments cansel each other, dipole moment is zero).
The London dispersion force (intermolecular force) <span>is a temporary attractive </span>force between molecules.
