Answer:
D) He did not multiply the chlorine and oxygen atoms by the coefficient 4.
Explanation:
The coefficient 4 at the beginning of the chemical formula indicates that there are four Ca(ClO3)2 molecules. Think of this as Ca(ClO3)2 × 4. This means that he had to multiply the number of atoms for each element by 4 as well, so he should've ended up with 4 total calcium atoms (which is correct), 8 total chlorine atoms, and and 24 total oxygen atoms. He did not get all these answers because he didn't multiply the chlorine and oxygen atoms by the coefficient 4.
In balanced equation there are same number of atoms in each element on both sides of the equation. unbalanced equation is when there are different number of atoms in each element on the both sides
None, it’s solar radiation
First of all, you should know the valence electron of atom.
Then add charge, In case of -ve ion & subtract, in case of +ve ion.
Explanation:
If the density of the object is more than that of water, it will sink. Otherwise it will float. The density of water is 1 g/mL.
Substance 1,
Mass, m = 450 g, Volume, V = 90 mL
Density = mass/volume
So,

It will sink.
Substance 2,
Mass, m = 35 g, Volume, V = 70 mL
Density = mass/volume
So,

It will float.
Substance 3,
Mass, m = 24 g, Volume, V = 12 mL
Density = mass/volume
So,

It will sink.