Answer:
number of energy levels
Explanation:
for example hydrogen and helium are in period 1 and they have 1 energy level
Answer:
Average atomic mass = 10.812 amu
Explanation:
The formula for the calculation of the average atomic mass is:
Given that:
<u>For first isotope, Boron-10:
</u>
% = 19.8 %
Mass = 10.013 amu
<u>For second isotope, Boron-11:
</u>
% = 80.2 %
Mass = 11.009 amu
Thus,
<u>Average atomic mass = 10.812 amu</u>
Visible and Ultraviolet Spectroscopy
Violet: 400 - 420 nm.
Indigo: 420 - 440 nm.
Blue: 440 - 490 nm.
Green: 490 - 570 nm.
Yellow: 570 - 585 nm.
Orange: 585 - 620 nm.
Red: 620 - 780 nm.
Hope this helps
1.679 × 10²³ g of PbO₂ is present in 4.23×10⁴⁴ particles of PbO₂.
<u>Explanation:</u>
First the number of particles is converted into moles by dividing it by the Avogadro's number and then moles multiplied by the molar mass, we will get the mass of PbO₂ in grams.
4.23×10⁴⁴/ 6.022×10²³ = 7.02×10²⁰ moles
Now we have to multiply this by the molar mass of PbO₂, that is 239.2 g/mol, we will get the mass in grams.
7.02×10²⁰ moles × 239.2 g/mol = 1.679 × 10²³ g of PbO₂
