I think the first question is talking about the ionic compound Sodium sulfide and it’s formula is Na2S.
And for the second question, i’m pretty sure it’d be a positive charge
Explanation:
Nuclear reactions are the reactions in which nucleus of an atom changes either by splitting or joining with the nucleus of another atom.
There are two types of nuclear reactions.
- Nuclear fission - In this process, large atomic nuclei splits into smaller nuclei.
- Nuclear fusion - In this process, two small nuclei combine together to form a large nuclei.
Both nuclear fission and fusion processes involve nuclei of atoms.
For example, 
Thus, we can conclude that statements which are true are as follows.
- Nuclear reactions involve the nuclei of atoms.
- The products of nuclear reactions are lighter than the reactants.
Answer:
Final velocity will be equal to 14 m/sec
Explanation:
We have given initial velocity u = 5 m/sec
Constant acceleration is given 
Time t = 6 sec
We have to find the final velocity
From first equation of motion
, here v is final velocity, u is initial velocity , a is acceleration and t is time
So 
So equal final velocity will be equal to 14 m/sec
It is more likely to be a metal. This is because metals are good heat conductors whereas non metals tend to be poor heat conductors.
Explanation:
It is given that,
Mass of cardinal,
Mass of baseball, 
Both cardinal and baseball have same kinetic energy. We need to find the ratio of the cardinal's magnitude
of momentum to the magnitude
of the baseball's momentum.

Kinetic energy is given by, 




So, 
So, the ratio of cardinal's magnitude of momentum to the magnitude of the baseball's momentum is 53 : 100