What is the symbol and number of protons in one atom of Arsenic and Argon?

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By looking at the Periodic Table in order to locate the element you are seeking. By doing this you will be able to pinpoint the exact number of protons of the elements.

Arsenic (AS) atomic - number of protons = atomic number 33

Argon ( Ar) - number of protons = atomic number 18

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To answer this question and others like it, use the Periodic Table and find the element you are looking for. On each element's block on the Periodic Table, there are two numbers; one is a whole number and the other is usually a decimal number. The decimal number represents the average atomic mass of an element. The whole number is called the atomic number and defines the number of protons (positively charged subatomic particles). It also indicates the number of electrons (negatively charged subatomic particles) IF the atom is neutral (not an ion). 

Using the Periodic Table, you can identify the number of protons of each element. Arsenic has the atomic number of 33 and therefore has 33 protons. Similarly Argon has 18 protons. Hope this helps! 

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Argon is at the far right of the periodic table of elements.  It is a noble gas, which means that it is really stable.  It has a high ionization energy as well (which is why it is stable).  The chemical symbol is Ar.  Its atomic number is 18.  That means Argon has 18 protons.   A typical Argon atom has 22 neutrons.  Also, it glows a really cool purple color when electricity is run through it. 

Arsenic's symbol is As.  It has an atomic number of 33.  That means that Arsenic has 33 protons.  It is classified as a metalloid.  A typical Arsenic atom will have 42 neutrons.  

For both atoms, if they are neutral in charge, they will have the same number of electrons as they do protons.  

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In brief, 

Arsenic: As, no. of protons = atomic number = 33

Argon: Ar, no of protons = atomic number = 18 

Hope this helps.

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