If an atom gains an electron and gets a negative charge because of it, it is a negatively charge ion AKA an anion.
Answer:
<em>the <u>valency of an element</u> is its combining capacity that is the number of electrons it requires to lose, gain or share in order to become neutral.</em>
[ An element can become neutral if it completes it's octet. That is if an element has 8 electrons in it'd outermost shell then it is considered neutral ]
- The valence of Magnesium is 2 because it requires to lose 2 electrons to become neutral.
- whereas, the valence of Oxygen is 2 because it needs to gain 2 electrons to become stable.
Hence they both have the same valence.
One may say that oxygen's valence is -2 while that of Magnesium is + 2. It's meaning is still the same but "-" sign indicates that oxygen will be gaining electrons in the process of becoming stable.
Answer:MnCO3+2H2O----->MnO2+ HCO3-+2e-+3H+
Explanation:The equation to be balanced is
MnCO3 ------> MnO2+HCO3-
The oxidation number of Mn changes from +2 in MnCO3 to +4 in MnO2
Therefore two electrons must be added to the right as shown below:
MnCO3 -------> MnO2+ HCO3-+ 2e-Now,there is one negative charge HCO3- and 1 negative charge on the two electrons making a total of -3 charges on the right. There is zero charge on the left.
To balance the equation,add3H+on the right,to cancel out the charges.
MnCO3 --------> MnO2+HCO3-+2e-+3H+
Adding H2O to balance Hydrogen and Oxygen atoms:
MnCO3+2H2O ------->MnO2+HCO3-+2e-+3H+
Explanation:
I think it is a true statement .
