A bond between two atoms that SHARE electrons
Answer:

Explanation:
We have the number
. Standard notation would basically be this number without the
part.
To get rid of this part, we need to move the decimal point 6 places to the left (we go left because it's negative 6, indicating division).
So, when we move the decimal point 6 places to the left, the resulting number is:
, with 5 zeros after the decimal point before a nonzero number.
Thus, the answer is
.
Answer:
4.15×10⁻²¹ moles of Sn
Explanation:
This question can be solved by a simple rule of three.
We know that 1 mol contains 6.02×10²³ particles.
In this case, our particles are the atoms, so:
6.02×10²³ atoms / 1 mol . 2500 atoms = 4.15×10⁻²¹ moles.
The knowledge of mol can be applied for everything:
A mol of molecules
A mol of atoms
A mol of a compound