Answer:
1.5*10^(-2)
Explanation:
0.015 is the answer for (3*10^2)*(5*10^-5)
(3*100)*(5*0.00001)
300*0.00005 = 0.015
1.5*0.001 = 0.015
Answer:
A <em><u>molecular formula</u></em> indicates the ratio of atoms in a molecule.
Explanation:
A molecular formula or chemical formula is a representation or indication of the number of atoms in a particular compound or molecule have in a specific specific proportion.
These are represented by the symbols of elements, numbers of atoms present and sometime other symbols. For example in water molecule there is one atom of oxygen and two hydrogen atoms.
Thus, the correct answer is : <em><u>molecular formula</u></em>
Answer:
a billion boron atoms are contained in a mass m= 2.21*10⁻¹⁴ gr of tetraborane
Explanation:
Since there are an Avogadro number (N= 6.023*10²³ molecules/mole) of molecules of tetraborane in a mole of tetraborane , and per each molecule there are 4 atoms of B . Then
number of moles n = a/(4*N)
where a= number of atoms
the corresponding mass of tetraborane m is
m= n*M
where M= molecular weight of tetraborane = 53.32 g/mol
then
m= n*M = a*M/(4*N)
replacing values
m= a*M/(4*N)= 1.0*10⁹ atoms of B * 53.32 gr/mole /( 4 atoms of B/molecule* 6.023*10²³ molecules/mole ) = 2.21*10⁻¹⁴ gr
m= 2.21*10⁻¹⁴ gr
