Answer:
The solvent
Explanation:
After the solid is recoverd by decanting the liquid, some solvent particles may still adhere to the solid.
In order to remove the solvent that may have adhered to the solid completely , the solid is washed before it is now dried.
Answer:
Yes
Explanation:
First remember that a significant figure are basically values that contribute to the precision of a value. In any scientific notation the values are significant figures because these values stay the same. In this case we have two significant figures which is 6 and 0, you can further prove that they are significant figures by converting the notation into standard form.

Negative so move the decimal point to the left:

6 and 0 are the significant figures in this standard notation because it's precise to it's actual value which is 6.0.
To sum up, the values you have on the left side of a notation are significant figures since they will not change no matter if it's standard or scientific notation meaning it's precise.
Hope this helps.
Answer:
Pb(NO₃)₂ + Na₂CrO₄ —> PbCrO₄ + 2NaNO₃
The coefficients are: 1, 1, 1, 2
Explanation:
Pb(NO₃)₂ + Na₂CrO₄ —> PbCrO₄ + NaNO₃
The above equation can be balance as follow:
Pb(NO₃)₂ + Na₂CrO₄ —> PbCrO₄ + NaNO₃
There are 2 atoms of Na on the left side and 1 atom on the right side. It can be balance by writing 2 before NaNO₃ as shown below:
Pb(NO₃)₂ + Na₂CrO₄ —> PbCrO₄ + 2NaNO₃
Now the equation is balanced.
The coefficients are: 1, 1, 1, 2
The charge of proton and electron is equal in magnitude that is
. The distance between electron and proton is
or
.
Force exerted on electron by proton is calculated as follows:

Here, k is Coulomb's constant,
is charge on proton,
charge on electron and r is distance between them.
Putting the values,

Now, according to second law of Newton,

Here,
is mass of electron and a is acceleration.
Also, 
Rearranging,

Thus, the acceleration of an electron in this atom is
.