Humans disturb the earth and because of this, the earth is weakened
Na2C2O4(aq) + CaCl2(aq) -----> 2NaCl(aq) + CaC2O4(s)
Here, CaC2O4(s) is a precipitate in the reaction as a result of precipitation reaction or double displacement reaction.
As we know that double displacement reaction two metal ions displaces each other from their salt solutions.
As we know that precipitation reaction is a reaction in which precipitate is formed.
Electronegativity
The tendency of an atom to pull electrons towards itself is called electronegativity.
It is the tendency of an atom to attract bonding pair of electrons towards itself. These atoms which are more electronegative are able to bear a negative charge and be stable.
Unlike electropositive elements which tend to lose electrons , electronegative elements hold on tightly to the electrons.
The electronegativity is measured using the Pauling Scale where the most electronegative element of the periodic table, Fluorine , is given a value of 4 and the rest of the elements have values lower than 4 according to the trends followed by their groups and periods.
The least electronegative element of the periodic table , Cesium has a value of 0.7 on the Pauling Scale.
Electronegativity increases when we move from left to right in the periodic table and it decreases (in general) when we move down the group.
(To know more about Electronegativity: https://brainly.in/question/5742635 )
C2H2 is the right answer I believe