# Green Pea Analogy

## by PakLiam

• 1,581 views

How large is an atom? How many atoms are in the leads of 12 lead pencils? Pencil leads are made of carbon atoms. Carbon has an atomic mass of 12. how can we visual this ?

How large is an atom? How many atoms are in the leads of 12 lead pencils? Pencil leads are made of carbon atoms. Carbon has an atomic mass of 12. how can we visual this ?

### Categories

Uploaded via SlideShare as Microsoft PowerPoint

### 5 Embeds469

 http://www.quia.com 273 http://gjismyp.wordpress.com 130 http://www.ualberta.ca 64 http://edmodoqa.edmodo.com 1 http://www.slashdocs.com 1

### Statistics

Likes
1
19
1
Embed Views
469
Views on SlideShare
1,112
Total Views
1,581

11 of 1 previous next

## Green Pea AnalogyPresentation Transcript

• Green Pea AnalogySome Initial ConceptsHow large is an atom? How many atoms are in the leads of 12 lead pencils?Pencil leads are made of carbon atoms. Carbon has an atomic mass of 12.Atomic mass is the mass of an atom. It is calculated as the sum of the number of protons and neutrons in theatom, because protons and neutrons make up the majority of the atoms mass. Each proton and neutron is givenan atomic mass of 1. Since carbon has six protons and six neutrons, its atomic mass is 12. Carbon also has sixelectrons, but these are extremely light compared to the protons and neutrons and do not contribute tocarbons integral atomic mass.Atomic mass is so light (1 atomic mass unit (amu) ∼ 1.66 x 10-24 g) that it is impractical to measure.Instead, scientists estimate atomic mass by measuring the mass of the element (in grams) which is equal invalue to the number of protons and neutrons in an atom of the element. The amount of an element with thismass (in grams) is called a mole. An atom of carbon has an atomic mass of 12, so a mole of carbon weighs 12grams. Placing 12 grams of carbon (pencil lead) beside 28 grams of silicon (sand) enables one to visually contrastthe atomic mass of carbon (atomic mass 12) to that of silicon (atomic mass 28). (The comparison is not entirelyvisual, since element density influences the volume of a mole of an element.)A mole of any element contains 602, 000, 000, 000, 000, 000, 000, 000 atoms of that element, that is 602sexillion US, 602 trilliard UK or 6.02 x 1023 atoms. This number is called Avogadros Number after AmedeoAvogadro (1776-1858) who discovered this number-of-atoms-in-a-mole relationship.What does this have to do with 12 pencil leads?Twelve pencil leads weigh approximately 12 grams, so have 6.02 x 1023 atoms in them.But what does 6.02 x 1023 atoms mean?
• 100 = 1One pea
• 101 = 1010 peas - spoonful
• 102 =10010 spoonfuls of peas - plateful
• 103 = 100010 platefuls of peas – a bag
• 104 = 10 000 10 bags of peas
• 105 = 100 000100 bags of peas - fridgeful
• 106 = 1 000 00010 fridges full of peas - an average bedroom
• 107 = 10 000 000Average house full from basement to attic with peas
• 109 = 1 000 000 000 100 houses full from basement to attic with peas- a small village
• 1012 = 1 000 000 000 000100 000 houses full from basement to attic with peas - a small city
• 1015 = 1 000 000 000 000 000A large city like New York covered 1 m deep with peas
• 1018 = 1 000 000 000 000 000 000A area like Kalimantan covered 1 m deep with peas
• 1020 = 100 000 000 000 000 000 000The land mass of China covered 1 m deep with peas
• 1021 = 1 000 000 000 000 000 000 000The land mass of the world covered 1 m deep with peas
• 1023 =100 000 000 000 000 000 000 000The entire surface of the earth plus 99 planets just like earth covered 1 m deep with peas
• 6.02 x 1023 = 602 000 000 000 000 000 000 000 = 602 earthsized planets = 12 = one mole = 1/18 the surfacecovered 1 m pencil of carbon area of the Sun deep with leads atoms peas