High School Chemistry : Help with Molecular Weight and Molar Mass
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Example Questions
Example Question #11 : Stoichiometry
How many protons does potassium-40 have?
The number of protons is equal to the atomic number of an element. The atomic number of an element can usually be found on the top right of the element box in the periodic table. The chemical symbol for potassium is K
Example Question #11 : Stoichiometry
What is the chemical symbol for an atom with 
To determine the chemical symbol of an atom we can use the atomic number because no two elements have the same atomic number. The atomic number is equal to the number of protons, and is usually located on the top left of the element's box in the periodic table. This atom has 8 protons, therefore the atomic number is 8. Using this information it can be determined that the chemical symbol for an atom with 8 protons is O, oxygen.
Example Question #281 : High School Chemistry
Elements in the periodic table are arranged according to their __________.
atomic mass
atomic number
relative activity
relative size
atomic number
The elements are arranged based on their atomic number. The atomic number can usually be found on the top left of each element's box. The atomic number increased from left to right as you move across the periodic table.
Example Question #281 : High School Chemistry
What is the mass in grams of 
To determine the mass in grams of 
The molecular mass of magnesium is 
In the above conversion, the moles cancel to leave the answer in grams.
Example Question #12 : Stoichiometry
How many moles of potassium are there in 
To determine the number of moles in 
Using this information we can convert grams to moles:
Example Question #11 : Stoichiometry
How many moles of tungsten are in 
To convert atoms to moles we need to know that there are 
Example Question #281 : High School Chemistry
How many atoms are in 
To determine the how many atoms are in 
Example Question #11 : Help With Molecular Weight And Molar Mass
What is the mass in grams of 
To determine the mass in grams of 
Now we have all of the information we need to perform the conversion:
Example Question #11 : Help With Molecular Weight And Molar Mass
How many atoms of sulfur are in 
The conversion of grams to atoms is a two-step process. First, we need to convert grams to moles using the molecular mass of sulfur. The molecular mass of sulfur can be found on the periodic table and is equal to
Then we will convert moles to atoms using our knowledge that 
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