About 30 (by my exact count, it's 32, but I may have missed one or counted it twice).
change your nnumber
87 is NOT a prime number.
36 elements were known in 1800.
If there was no binary, there would be no computer.
Yes, in the same sense that there are 99 elements and 10 elements. MORE than 100 elements are known.
A prime number is a number that is not divisible by any whole number.
It is: 8 times 8 = 64
9
Approx. 20 elements were known in 1800.
Yes, 52 is a square number: 52 x 52 = 2704
...as a solid.
25-75 USD or so