Answer : The formal charge on the C is, (-1) charge.
Explanation :
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
The given molecule is, 
As we know that carbon has '4' valence electrons and hydrogen has '1' valence electron.
Therefore, the total number of valence electrons in = 4 + 3(1) + 1 = 8
According to Lewis-dot structure, there are 6 number of bonding electrons and 2 number of non-bonding electrons.
Now we have to determine the formal charge on carbon atom.
Formula for formal charge :
The formal charge on the C is, (-1) charge.
Pressure can be defined as the force acting on a perpendicular surface per unit area.
Force exerted by a man of mass 100 kg wearing snow shoes = m.a
Where m = mass of the man = 100 kg
a = acceleration due to gravity= 9.8 
Force exerted by the man of mass 100 kg = 
Force exerted by woman of mass 60 kg = 
Force exerted by 100 kg man is greater than that exerted as 60 kg woman. The area on which this force is acting determines the pressure. Pressure is inversely proportional to the area on which the force acts. Therefore, the pressure exerted by 100 kg man wearing snow shoes is less than the pressure exerted by a 60 kg woman woman wearing high heels as the force acts over a larger area when the man wears snow shoes when compared to the force exerted over a smaller area in case of the woman wearing high heels.
The silicon wafer contains 20.96 g of silicon.
The mole of a substance is related to its mass and molar mass by the following equation:
<h3>Mole = mass / molar mass ....... (1)</h3>
Making mass the subject of the above equation, we have
<h3>Mass = mole × molar mass ..... (2)</h3>
With the above formula (i.e equation 2), we can obtain the mass of silicon in the wafer as follow:
Mole silicon = 0.746 mole
Molar mass of silicon = 28.09 g/mol
<h3>Mass of silicon =? </h3>
Mass = mole × molar mass
Mass = 0.746 × 28.09
<h3>Mass of silicon = 20.96 g</h3>
Therefore, the mass of silicon in the wafer is 20.96 g
Learn more: brainly.com/question/24639749
Boyle's law gives the relationship between pressure and volume of gas.
for a fixed amount of gas, at constant temperature the pressure of gas is inversely proportional to its volume.
PV = k
where P - pressure, V - volume and k - constant
P1V1 = P2V2
where parameters for the first instance are on the left side and parameters for the second instance are on the right side.
substituting the values in the equation
1.2 atm x 1.0 L = P x 4.0 L
P = 0.3 atm
new pressure is 0.3 atm
