The balanced reaction is
Ca + 2H2O → Ca(OH)2 + H2
Here this reaction can be compared with
A + BC ---> AB + C
So here one reactant (A) is accepting a group which is being given by another compound (BC) however the A is not giving any group / element or ion
So this single displacement
Similarly in the given reaction
the anion OH- is only being replaced
The element Ca accepts OH- and H2O loses the same group to form new element H2
So the correct answer is
Single replacement also known as single displacement
Answer:
The correct option is b. false
Explanation:
The distance between the nucleus of an atom and it's outermost shell is called is atomic radius. The atomic radius of an Iron atom (Fe) is 0.126 nm or 1.26 angstrom. The distance between the nuclei of two Iron atoms will be 1.26 × 2 = 2.52 angstroms.
Since 2.52 angstroms is lower than 4 angstroms, the correct option is false
Consider this balanced chemical equation:
2 H2 + O2 → 2 H2O
We interpret this as “two molecules of hydrogen react with one molecule of oxygen to make two molecules of water.” The chemical equation is balanced as long as the coefficients are in the ratio 2:1:2. For instance, this chemical equation is also balanced:
100 H2 + 50 O2 → 100 H2O
This equation is not conventional—because convention says that we use the lowest ratio of coefficients—but it is balanced. So is this chemical equation:
5,000 H2 + 2,500 O2 → 5,000 H2O
Again, this is not conventional, but it is still balanced. Suppose we use a much larger number:
12.044 × 1023 H2 + 6.022 × 1023 O2 → 12.044 × 1023 H2O
These coefficients are also in the ratio of 2:1:2. But these numbers are related to the number of things in a mole: the first and last numbers are two times Avogadro’s number, while the second number is Avogadro’s number. That means that the first and last numbers represent 2 mol, while the middle number is just 1 mol. Well, why not just use the number of moles in balancing the chemical equation?
2 H2 + O2 → 2 H2O
Not sure what you are asking. I have two possible answers though...
It could either be more negatively charged, or valence electrons.
The more away from the nucleus a electron is, the more negatively charged it is.
The electrons on the outermost electron shell is valence electrons.
Again, I don't know what you were asking, but one of these answers may be correct.