1 mole --------------- 6.02 x 10²³ atoms
( moles iron) -------- 5.0 x 10²⁵ atoms
( moles iron ) = 5.0 x 10²⁵ x 1 / 6.02 x 10²³
moles iron = 5.0 x 10²⁵ / 6.02 x 10²³
= 83.05 moles of iron
hope this helps!
Slow chemical change
It is a chemical change because the erosion is due to the chemical reaction between the acid and the in the rain and the calcium carbonate.
It is slow due to the concentration of acid is low.
Answer:
The percentage of N in the compound is 0.5088
Explanation:
Mass of compound = 8.75 mg = 8.75×1000 = 8750 g
Mass of N2 = number of moles of N2 × MW of N2 = 1.59 × 28 = 44.52 g
% of N in the compound = (mass of N2/mass of compound) × 100 = (44.52/8750) × 100 = 5.088×10^-3 × 100 = 0.5088
As the temperature increases, the solubility of the solute in the liquid also increases. This is due to the fact that the increase in energy allows the liquid to more effectively break up the solute. The additoin of energy also shifts the equilibrium of the reation to the right since it takes energy to dissolve most things and you are adding more of it (this is explained with Le Chatlier principles).
I hope this helps and also I assumed that your question involved the solubility of an ionic substance in a solvent like water. If that was not your question feel free to say so in the comments so that I can answer your actually question.
First, isotopes <u>are the atoms of a single element whose nuclei have a different number of neutrons</u>, and therefore, differ in mass numbers. You should know that atoms are formed by a nucleus that has a small size and is made up of protons and neutrons. The nucleus is surrounded by a cloud of electrons, which are found in a region of the atom called the cortex.
The mass number, represented as A, <u>is the sum of the number of protons and neutrons in the nucleus</u>. On the other hand, the atomic number (Z) is <u>the number of protons that exist in the nucleus.
</u>
The isotopes of an element X are represented as follows,
<em>(see first attached picture)</em>
It should be noted that the number of neutrons of a chemical element can be calculated as the difference A-Z.
<u>The atomic and mass numbers of bismuth with 125 neutrons are</u>:
Z = 83
A = 83 + 125 = 208
Thus, the atomic symbol of the bismuth isotope with 125 neutrons is:
<em>(see second attached picture)</em>
