how many atoms are present in 0.5g of atoms of silicon?
Answers
Explanation:
Atoms are extremely small relative to the scale of human life. Scientists use a unit called a mole to describe large quantities of atoms and other small things. One mole is equal to 6.022 x 10^23 particles. This number is called Avogadro's number. These particles can be individual atoms, molecules of a compound or any other particle being observed. In order to calculate the number of atoms in a one gram sample of any substance, you must calculate the number of moles of that substance based on its molar mass. Then, you can use Avogadro's number to calculate the number of particles.
Real-Life Application
A real-life application of Avogrado's number applies to the iconic example of examining the density of what weighs more: a ton of feather or a ton of something very heavy like bricks or metal weights. The lighter feathers require a greater number to create the same density as the heavier objects.
Find Atomic Mass
Before determining atomic mass, you need to look up the elements on the periodic table and note their atomic mass numbers under the element's chemical symbol. Pure elements have an atomic mass that is also the molar mass or amount of grams per mole.
Add Atomic Mass
First, add the atomic mass of each atom in the compound. The atomic mass of an element is the mass of one mole of that element. Atomic masses are given in atomic mass units. One atomic mass unit is equal to one gram per mole. When you add these together for a compound, you get the molar mass of that compound. For example, silicon dioxide consists of one silicon atom and two oxygen atoms. The atomic mass of silicon is 28 grams and the atomic mass of oxygen is 16 grams. Therefore, the total mass of one mole of silicon dioxide is 60 grams.
Divide Number of Moles
Divide one gram by the molar mass of the compound. This gives the number of moles of the compound in a one gram sample. As an example, one gram of silicon dioxide divided by 60 grams per mole gives around 0.0167 moles of silicon dioxide.
Multiply by Avogadro's Number
Next, multiply the number of moles by Avogadro's number. This formula yields the number of molecules in one gram. For example, 0.0167 moles of silicon dioxide times 6.022 x 10^23 equals around 1 x 10^22 molecules of silicon dioxide.
Multiply by Atom Number
Finally, multiple by the number of atoms in one molecule. For example, each molecule of silicon dioxide contains three atoms. Therefore, there are around 3 x 10^22 atoms in one gram of silicon dioxide.
References
About the Author
Did you find this page helpful?
Related Articles
How to Calculate Millimoles to Milligrams
How to Calculate Mass in Grams of a Molecule
How to Convert Atoms to Grams With a Calculator
How to Convert AMU to Mole
How to Find the Percent of Concentration of Copper Sulfate in Copper Sulfate Pentahydrate
What Happens When SO2 Reacts With Steel?
What Is the Difference Between Molar Mass & Molecular Weight?
From the WebPowered by

J.K. Rowling Confirms a Hermione Theory We Suspected All Along

The Chilling Selfie Teens Took Before a Tragic Bridge Collapse

Violent Cities from Around the World to Avoid at All Cost

Science Reveals What Women Find Most Physically Attractive

Put Salt in the Corners of Your House and Watch What Happens

Little Lucy From 'Narnia' is Absolutely Gorgeous Now at 23

The Real Reason Your Dog Stares at You

10 Scientifically Proven Side Effects of Growing a Beard
How to Calculate Millimoles to Milligrams
•••
Updated March 13, 2018
By Sean Lancaster
Quantities of chemicals are measured in grams, but the amounts that react based on a chemical reaction are expressed in moles according to the stoichiometry of the equation. The term moles refers to a collection of particles and represents a total of 6.02 x 10^23 distinct molecules. To measure directly how many particles are present, you need to convert the number of particles into a weight. Weight is measured on a balance and has units of grams. To convert the number of moles to weight requires the knowledge of the composition of the material.
Determine the formula weight of the compound of interest. The formula weight is calculated by adding the atomic weight of the atoms in the chemical formula of the compound of interest. The atomic weights of the elements are found on the periodic table of elements. For example, you need to find the formula weight for iron rust with the chemical formula of Fe2O3. Look up the atomic weight of iron and oxygen on the periodic table. The atomic weight of iron is 55.845 and the atomic weight of oxygen is 16.000. Add the weight of each atom in the compound:
2 * 55.845 + 3 * 16.000 = 111.69 + 48.00 = 159.69.
This is the weight in grams of 1 mole of the compound.
Convert the weight of one mole to the weight of one millimole. Based in the metric system, one millimole is the same as one mole divided by 1,000. Therefore, the weight of one millimole is equal to the weight of one mole divided by 1,000. Continuing the example:
Answer:
Here is your answer I hope this answer is help full
