A, a heterogeneous mixture is a mixture where all the particles are not made up of one uniform composition. you can distinguish the different particles
The term for a push or pull is called Force.
If you only want to balance nuclear reactions, then you should know that number of nucleons are conserved before and after nuclear reaction. Also, charge is conserved as well.
Other things which are conserved in a nuclear reaction are:
Conservation of:
1. Parity
2. Spin
3. angular momentum(vector sum of intrinsic spin and orbital angular momentum)
4. linear momentum
5. Isotopic spin
6. Energy
B because it can stabilize
46 is the answer. because if you add 26 and 20 that is the mass
