The isotope notation : 
<h3>
Further explanation
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Given
53 protons and 20 neutron
Required
The isotope notation
Solution
Isotopes are elements that have the same atomic number with a different mass number
The following element notation,

X = symbol of element
A = mass number
= number of protons + number of neutrons
Z = atomic number
= number of protons = number of electrons, on neutral elements
So the mass number of element = 5 + 6 11
Atomic number = 5
The symbol :

Aluminium family has 3 electrons in their valence shell....i hope its correct..。◕‿◕。
Answer:
<h2>(1). electron electron repulsion</h2><h2>(2). repulsion </h2><h2>(3). attraction </h2><h2>(4). maximum attraction </h2><h2>(5). attractive </h2><h2>(6). repulsive </h2><h2>(7). maximum attraction </h2><h2>(8). molecule </h2>
Explanation:
The same charges repel each other while opposite charges attract each other. During electron-electron interaction repulsion take palace because the electron has negative charges. Nucleus has positive charges so the interaction between two nucleus results in the form of repulsion. When interaction takes place between nucleus and electron then attraction takes place between nucleus and electrons due to opposite charges.
The formation of a bond that takes place due to the sharing of the electrons is known as a covalent bond and thus the covalent molecule is formed.
The sample will lose half of its mass after 4 hours. The half life.
82=4
The sample will lose half of the remaining four after another half life.
42=2 Hope this helps! :)
Covalent and ionic bonds are two different types of chemical bonding. Covalent bonds involve the sharing of electrons between 2 atoms while ionic bonds involve the complete transferring of electrons from one atom to another. Covalent bonds usually form between two nonmetals while ionic bonds usually form between a metal and a nonmetal.
I hope this helps. Let me know if anything is unclear.