Answer: In CaF2, the oxidation number of Ca is +2
, and that of F is -1
. In H2SO4, the oxidation number of H is +1
, that of S is +6
, and that of O is -2
. In CaSO4, the oxidation number of Ca is +2
, that of S is +6
, and that of O is -2
. In HF, the oxidation number of H is +1
, and that of F is -1
Endothermic reaction is the answer.
Atomic number (Z) of tungsten is 74
Mass number (A) of tungsten is 184
Now:
Atomic number of an element = Number of protons = Number of electrons
Mass number = Number of Protons + Number of neutrons
In the case of tungsten
Total Number of electrons = 74
Jeffrey has already added 21 electrons
Number of electrons needed = 74 - 21 = 53
Ans (D) 53 more electrons are needed to complete the neutral atom of tungsten.
A water molecule, abbreviated as H2O, is an example of a polar covalent bond. The electrons are unequally shared, with the oxygen atom spending more time with electrons than the hydrogen atoms. Since electrons spend more time with the oxygen atom, it carries a partial negative charge.
