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>
This is because their tails are hydrophobic and their heads are hydrophilic. Hydrophobic meaning dislikes being near water and hydrophilic meaning likes to be near water. Therefore, they will orientate themselves in such a manner that the heads are facing externally and all the tails are facing together protected by the hydrophilic heads. google a photo of lipid chains in water if you are still confused. I'm not sure if that is what you are asking, but I hope it helps.
The molar mass of NH4NO3 in g/mol is 80g/mol.
HOW TO CALCULATE MOLAR MASS:
The molar mass of a compound can be calculated by summing the atomic masses of its constituent elements.
In ammonium nitrate (NH4NO3), there are nitrogen, hydrogen, and oxygen elements.
- Atomic mass of nitrogen = 14
- Atomic mass of oxygen = 16
- Atomic mass of hydrogen = 1
Molar mass of NH4NO3 = 14 + 1(4) + 14 + 16(3)
Molar mass of NH4NO3 = 80g/mol
- Therefore, the molar mass of NH4NO3 in g/mol is 80g/mol.
Learn more about molar mass at: brainly.com/question/8101390?referrer=searchResults
Answer:9.49g/mL
Explanation:
Mass of toy = 43.672g
Volume of water = 34.4mL
Volume of toy + volume of water = 39mL
Volume of toy = 39 — 34.4 = 4.6mL
Density = Mass /volume
Density = 43.672/4.6 = 9.49g/mL