Answer: The mass of electrons is mostly ignored because electrons are extremely small compared to neutrons and protons.
Explanation: A proton is about 1,836 times the size of an electron.
On the periodic table, the atomic number for each element can be found. This number is found by measuring the weight of 6.02 x 10^23 atoms of the element in grams. Electrons aren't ignored when finding exact math, but for the sake of simplification high school teachers will generally have you only count the number of protons and neutrons when calculating the mass of atoms.
<h2>~<u>Solution</u> :-</h2>
- Here, to find the atomic mass of element, we must;
We know that,
- 4.6 x $ \sf{10^{22}}$ atoms of an element weigh 13.8g.
Thus,
The atoms of $ \sf{ 6.02 \times 10^{13}}$ will weigh;


- Hence, the molar mass (atomic mass) will be <u>180.6 g.</u>
Atoms are the smallest form of the substance. examples of atoms are in elemental forms such as copper, helium, silver. Diatomic molecules are made up of identical atoms. Examples are I2.. F2 and Br2. Formula units are those compounds that are made up of two or more elements such as -No2, KMnO4,<span>C3H8, MgCl2, HgBr2, Ba(OH)2</span>
-<u><em>Oxygen</em></u>
According to Google these are the percentages of the <em>Earths Atmosphere</em>
<em>1</em> 78% - Nitrogen
<u>2</u> 21% - Oxygen
<em>3</em> 0.9% - Argon
<em>4 </em>0.3 - Carbon Dioxide with very small percentage of other elements.