Answer:
b. proton
Explanation:
The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an electric charge of −1, which is equal but opposite to the charge of a proton, which is +1.
<span>They are all units of volume as are, Cubic Metres, Cubic Inches and Cubic Feet.
1mL and 1 cubic centimetre (cc) are the same.
Any one of the above is used to indicate the Density of substances which are compared to the density of pure water. By multiplying the Density of water by the Specific Gravity of the substance (Liquid or Solid), its density and, by calculation, it mass can be found. (cc and cmÂł are used for the solid materials. (a mL or Litre of copper or other solid doesn't quite sound right as they are used for liquid volume.</span>
Answer : The final pressure of the gas is, 
Explanation :
Boyle's Law : It is defined as the pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles.

or,

where,
= initial pressure = 545 mmHg
= final pressure = ?
= initial volume = 775 mL
= second volume = 171 mL
Now put all the given values in the above equation, we get:


Therefore, the final pressure of the gas is, 
I think the mass the mass was less than the original because a gas was released into the atmosphere. The mass in a chemical reaction is constant in a closed system according to conservation of mass law. However, if a chemical reaction is completed in an open system, mas changes may occur. In our case i think the change in mass was due to the release of hydrogen gas from the reaction to the atmosphere.
Answer:
0.302L
Explanation:
<em>...97.1mL of 1.21m M aqueous magnesium fluoride solution</em>
<em />
In this problem the chemist is disolving a solution from 1.21mM = 1.21x10⁻³M, to 389μM = 389x10⁻⁶M. That means the solution must be diluted:
1.21x10⁻³M / 389x10⁻⁶M = 3.11 times
As the initial volume of the original concentration is 97.1mL, the final volume must be:
97.1mL * 3.11 = 302.0mL =
0.302L