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.
P1V1/T1=P2V2/T2 P2=1/2 P1 V1=1 T1=298K
1 P1/298= (1/2) P1V2/373 cross P1
1/298=1/2V2/373
1/298=1/V2 746
v2=746/298
V2=2.5L
The percentage composition of this compound : 40%Ca, 12%C and 48%O
<h3>Further explanation</h3>
Given
20.0 g of calcium,
6.0 g of carbon,
and 24.0 g of oxygen.
Required
The percentage composition
Solution
Total mass of compound :
=mass calcium + mass carbon + mass oxygen
=20 g + 6 g + 24 g
=50 g
Percentage composition :
When solid <span>iron (iii) hydroxide is dissolved into water, it ionizes or it dissociates into ions. These ions are the iron (iii) ions and the hydroxide ions. Iron(III) oxide is classified as a base when in aqueous solution since it produces hydroxide ions. It is a weak base so it does not completely dissociate into the solution. The dissociation equation would be:
Fe(OH)3 <-----> Fe3+ + OH-
To write a complete reaction, the reaction should be balanced wherein the number of atoms of each element in the reactant side and the product side should be equal. Also, the phases of the substances should be written. We do as follows:
</span>
Fe(OH)3 (s) <-----> Fe3+ (aq) + 3OH- (aq)
