Answer
(a) Number of protons in $ ^{238}_{92}U$ is $Z=92$
(b) number of neutrons in $ ^{202}_{80}Hg$ is $N=122$
(c) $ 41 $ electrons are orbiting $ ^{93}_{41}Nb$ nucleus
Work Step by Step
(a) $ ^{238}_{92}U$
Comparing with $ ^{A}_{Z}X$
we get
$A=238$
$Z=92$
so number of protons in $ ^{238}_{92}U$ is $Z=92$
(b) $ ^{202}_{80}Hg$
Comparing with $ ^{A}_{Z}X$
we get
$A=202$
$Z=80$
number of neutrons $N=A-Z$
$N=202-80=122$
no of neutron $N=122$
so number of neutrons in $ ^{202}_{80}Hg$ is $N=122$
(c) $ ^{93}_{41}Nb$
Comparing with $ ^{A}_{Z}X$
we get
$A=93$
$Z=41$
so number of protons in $ ^{93}_{41}Nb$ is $Z=41$
since atoms are electrically neutral number of protons is equal to number of electrons.
so$ 41 $ electrons are orbiting $ ^{93}_{41}Nb$ nucleus
