Answer:Hummingbirds have long, needlelike beaks they use to probe deep into flowers. The hummingbird's beak is just a protective sheath for its tongue, which is actually what the hummingbird is using to get the nectar out of the flower. The tip of their tongue is forked and has little hairs all over it.
Explanation:
Answer:
Only
gives spontaneous reaction.
Explanation:
A redox reaction will be spontaneous if standard reduction potential (
) of the reaction is positive. Because it leads to negative standard gibbs free energy change (
), which is a thermodynamic condition for spontaneity of a reaction.

Where
and
represents standard reduction potential of reduction half cell and standard reduction potential of oxidation half cell.
(1) Oxidation:
; 
Reduction:
; 
So, 
Hence this pair will give spontaneous reaction.
(2) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
(3) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
(4) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
Answer:
A
Explanation:
Argon has 17 protons and 18 neutron
atomic number is the same as the protons number.