7. FeCl, and FeCl3 are two compounds of iron. (Fe, Atomic No:26)
(a) Calculate the oxidation states of Iron in these compounds.
(b) Write the subshell electronic configuration of Fe* ions.
(c) Explain the reason for exhibiting such variable valences.
(d) Write the abnormal electronic configuration of chromium and co
reason behind it. (Cu, Atomic No:29)

The table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.

Apiece of metal with a length of 1.42 cm was measured using four different instruments. which of the following measurements is the most accurate?

An atom of lithium-7 has an equal number of(1) electrons and neutrons(2) electrons and protons(3) positrons and neutrons(4) positrons and protons