Boiling Water is a physical change. When water gets to a certain temperature, it's boiling point starts.
B is the correct answer! I learned this in class last week :)
The atomic mass on the periodic table represents the sum of number of protons and number of neutrons.
Atomic mass = Number of protons + number of neutrons
Hope this helps!
The total atomic number must be the same on each side. The total mass number must be the same on both side.
<span>On the RHS, for the mass number, we have 257 + 4 = 261 (the 4 comes from the 4 neutrons). That means the mass number of the missing piece on the LHS is 261 - 247 = 14. </span>
<span>One the RHS, for the atomic number we have a total of 104 since the 4 neutrons are all neutral. On the LHS, we have this: 104 - 98 = 6. </span>
<span>The missing piece is a nucleus of carbon 14. Done in your style, it is 14/6C</span>
