
<em>Chemists use the mole unit to represent 6.022 × 10 23 things, whether the things are atoms of elements or molecules of compounds. This number, called Avogadro's number, is important because this number of atoms or molecules has the same mass in grams as one atom or molecule has in atomic mass units. </em>
hope helpful~
Answer:
B. The rate constant is the reaction rate divided by the concentration
terms.
Explanation:
The rate constant can be determined from the rate law because it is the reaction rate divided by the concentration terms. I hope I could help! :)
The molecular formula for compound is
mass of compound is 0.670 g.
To calculate number of atoms first calculate number of moles in the compound as follows:

Molar mass of
is 283.886 g/mol, thus,

Thus, number of mole of
is 0.00236 mol.
From the molecular formula 1 mole of
has 2 mol of P (phosphorus) and 5 mol of O (oxygen).
Thus, number of moles of P and O in 0.00236 mol of
will be:

Similarly,

Now, in 1 mol of an element there are
atoms.
Number of atoms of P will be:

Similarly, number of atoms of O will be:

Total number of atoms will be sum of number of atoms of P and O:

Therefore, total number of atoms in
will be
.
Mezoic era began 252m years ago and ended 6.6m years ago.
It was a time of geological and biological transition. During this era the continents began to drift to their present configuration.
3 of the largest mass extinction occurred at this era. One which include the dinosaurs.
I hope this helped. :)