A physical change would be 3) ice cream melting. 1) and 2) are combustion reactions, which are chemical with oxygen, and 4) is an oxidation reaction, also with oxygen. A phase change, or melting, is not a chemical change but a physical one. Therefore 3) ice cream melting is the answer
If you’re asking to balance the equation then:
Pb(NO3)2(aq) + 2KCl(aq) -> 2KNO3(aq) + PbCl2(s)
Just remember: the equations at the end is Cl not C12
Note: the small number on the bottom (subscripts) apply to the one element if it’s inside the bracket and if the small number is on the outside of the bracket it applies to all the elements. For example the 3 in (NO3)2 applied only to the O (oxygen) and the 2 applies to both N and O but don’t forget it’s multiplied. So it would be 2 N’s and 6 O’s bc the 3 multiplies with the 2 only for the O.
The Atomic Number.
-Hope this helps!
Answer:
The atomic weight of lead is 207.2169 amu
Explanation:
Step 1: Data given
Lead has 4 isotopes:
⇒ 203.97302 = 1.4 %
⇒ 205.97444 = 24.1 %
⇒ 206.97587 = 22.1 %
⇒ 207.97663 = 52.4 %
Step 2: Calculate the atomic weight of lead
Atomic weight = 203.97302 * 0.014 + 205.97444*0.241 + 206.97587 *0.221 + 207.97663 * 0.524
Atomic weight = 207.21688371 ≈ 207.2169 amu
The atomic weight of lead is 207.2169 amu
<span>In polar coordinates, the origin is called the pole. Polar coordinate system is actually a two dimensional coordinate system. In this type of system the reference point is known by the name of pole. I hope that this is the answer that you were looking for and the answer has come to your desired help.</span>
