60 elements! I don't exactly know every element known, so if you are asking that, please tell us, but what I do know is that there were 60 elements in the periodic table by 1860.
<u>Answer:</u> 3 neutrons are produced in the above nuclear reaction.
<u>Explanation:</u>
In a nuclear reaction, the total mass and total atomic number remains the same.
The nuclear reaction for the fission of Americium-244 isotope follows:

<u>To calculate Y:</u>
Total mass on reactant side = total mass on product side

Hence, 3 neutrons are produced in the above nuclear reaction.
Answer:
I just did the assignment it's "decreases"
Explanation:
If you guys came from Ed-genuity (i'm writing it like that because apperantly that is a swear word?) That means the next questions are "As you move from left to right across the periodic table, electronegativity..." and "As you move from top to bottom within a group, the first ionization energy...".
for electronegativity, it's increases and for ionization energy it's decreases. Hope this helps!