Okay, so even if I just gave you the answers, your teacher needs work on it too so it'll be easier/better if I just explain how to do it.
Basically, both sides need to have the same number of molecules. To do this, we make charts. This is the first side of number one:
Na - 1
Mg- 1
F - 2
The subscript gives F two molecules, and the other ones only each have one. This is the second side:
Na- 1
Mg- 1
F- 1
So they're not equal. To fix this, we add coefficients. These are numbers that are going to appear in the front of each compound/element and changes the number of molecules of the WHOLE compound/element. We need two F on the second side, so we'll put a coefficient of 2 in front of NaF. The new chart for the second side is this:
Na- 2
Mg- 1
F- 2
Now we've fixed the F, but now Na is off! So let's go to the first side again and see what we can do. We can put a 2 in front of the Na. The new chart is this:
Na- 2
Mg -1
F- 2
Now both sides are the same. The full new equation is:
2Na + MgF(sub2) = 2NaF + Mg
Basically, do this for all of them. Feel free to ask more questions.
Answer:
B. Ca(OH)2(s)+CO2(aq)-CaCO3(s)+H2O(aq)
"X" in the reaction above is acetic acid with a chemical formula CH3COOH. The chemical reaction would be NaOH + CH3COOH = NaCH3COO + H2O. This is a neutralization reaction in which it produces a salt and water. The salt produced is called sodium acetate.
The valence electron determines whether an ionic or covalent bond develops between two atoms.
An atom's outer shell electrons, known as valence electrons, can take a role in the creation of chemical bonds. When two atoms establish a single covalent bond, normally, both atoms contribute one valence electron to create a shared pair.
Ionic bonds, also known as electrovalent bonds, are a type of linkage created in a chemical molecule by the electrostatic attraction of ions with opposing charges. When one atom's valence (outermost) electrons are permanently transferred to another atom, a bond of this kind is created. The one or two and three are lost and gained in ionic bond formation, but particles with four valence electrons are neither lost nor gained. The four electrons are generally shared to form a covalent bond.
Hence, the valence electron decides the type of the bond.
To know more about Electrostatic attraction.
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