When the momentum of a proton is changed by an amount $P_0$,the corresponding change in the de-Broglie wavelength is found to be $0.25\%$. Then,the original momentum of the proton was

An ovule which becomes curved so that the nucellus and embryo sac lie at a right angle to the funicle is called:

Which of the following is included in biochemistry?

Consider the following statements:
$(I)$ The radius of an anion is larger than that of the parent atom.
$(II)$ The ionization energy generally increases with increasing atomic number in a period.
$(III)$ The electronegativity of an element is the tendency of an isolated atom to attract an electron.
Which of the above statements is/are correct?

$NH_3 + O_2 \xrightarrow[\Delta]{Pt} A + H_2O;$
$A + O_2 \to B$
$B + O_2 + H_2O \to C$
$A, B$ and $C$ are:

Which of these is least likely to act as a Lewis base?