John Dalton

John DaltonPresentation by Chidimma and sabrina

Chemistry: sect. 2

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Daltons Life

Born on September 6th, 1766Ran a boarder school with his brother at the age of 15Self-taught in French,Latin, German, science, and mathWas well-versed in chemistry, journalism, meteorology Proved that color- Blindness was hereditaryDevised Dalton's gas law to explain the behavior of gases Was given the honor of election into the royal societyNever married or had children, and remained a Quaker for his entire life

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Scientific achievements:

1. Color blindnessDalton mistook red as a light shade of pink, and saw warmer colors like yellow, red, and orange as simply being different shades of yellowDalton struggled with his condition at a young age: he embarrassed his family by buying his mother a pair of red bloomers as a gift, thinking they were pink Once, as a young adult, when he was to visit the King for a royal celebration, he was required to wear grey, but wore blue instead

John Dalton described his own color blindness in 1794. In common with his brother, he confused scarlet with green and pink with blue. Dalton supposed that his vitreous humor was tinted blue, selectively absorbing longer wavelengths. He instructed that his eyes should be examined after his death, but the examination revealed that the humors were perfectly clear. In experiments presented here, DNA extracted from his preserved eye tissue showed that Dalton was a deuteranope, lacking the middlewave photopigment of the retina. This diagnosis is shown to be compatible with the historical record of his phenotype, although it contradicts Thomas Young's belief that Dalton was a protanope.

Dalton struggled with his condition at a young age he embarrassed his family by buying his mother a pair of red bloomers, mistaking them as pink, as a gift. Then, as a young adult, when set to visit the King for a celebration, he was required to wear grey but wore blue instead. Dalton mistook red as a light shade of pink, and saw warmer colors like yellow, red, and orange as simply being different shades of yellow.He tested his theory by having he, himself, and other boys observe the color of a red flower and compare perceptions of color.

Dalton theorized that the reason why he had been born color blind was due to discoloration of the aqueous humor, the liquid of he eyeball, was blue andTherefore filtered other colors, and that colorblindness was hereditary. He requested that when he died, for there to be an examination of his death; though it was proven that colorblindness was hereditary, Daltons beliefof the blueus eyeliquid was incorrect. It was found that condition wasnt caused simply by the eye itself, but the sensory power. 3

Color blindness (contd)

What Dalton Theorized:

Eyes filtered out all other colors except for blue, because the aqueous humor (eye liquid) was blue in colorColorblindness was hereditary

What was proven:Colorblind gene found in DNA, could be passed down

Aqueous humors were clear; colorblindness is caused by a sensory problem aqueous humor(eye liquid)

aqueous humorWhat Dalton Theorized:Colorlindness was hereditaryEyes filtered out all other colors except for blue, because the aqueous humor (eye liquid) was blue in color

What was proven:Colorblind gene found in DNA, could be passed down Aqueous humors were clear; colorblindness is caused by a sensory problem,

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2. GAS LAWUsing his knowledge of the properties of water vapor from earlier experiments, Dalton created his own gas law to find atmospheric pressure from pressure of gases in the air

Hydrogen Water Vapor Oxygen Nitrogen Water Vapor Oxygen

PressureTOTAL = P1 + P2 + P3 + etc.

NOTECARD: Through studying the behavior of gases and conducting experiments, Dalton found that air is made up of different elements and that atmospheric pressure equals the individual pressure given off by the chemicals present in air and so he made Daltons Gas Law to calculate atmospheric.

Nitrogen, oxygen, hydrogen, water vapor

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from Gas laws to the atomic theory

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Dalton began to explore the concept of atoms, and while he was developing hr atomic theoryHe carried over his knowledge from experiments he did with 6

3. Atomic TheoryAll matter is made of atoms

Atoms of the same element have similar properties; different elements have different atoms Different atoms have different masses from each other Atoms combine into whole numbers

CH4 + 2O2CO2 + 2H2O4 hydrogen4 Oxygen4 hydrogen2 Oxygen1 carbon1 carbon

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NOTECARD:1: all matter is made up of units of matter, called atoms which

4) Atoms combine into whole number ratiosChemical reactions are formed by the rearranging of atoms

CH + 2O2 + CO2 + 2H2O

All matter is made of atomsAtoms of the same element have similar propertiesDifferent atoms have different masses from each otherAtoms combine into whole numbers numerical ratios

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Atomic Theory (contd)Dalton Used the atomic theory to explain his billiard ball model of the atom, which represents the atom as a small and solid ball of mass

Dalton stated that there were different kinds of atoms, just as there are different colors and types of billiard ballsCesiumPalladiumCalciumBoron

All matter is made of atomsAtoms of the same element have similar propertiesDifferent atoms have different masses from each otherAtoms combine into whole numbers numerical ratios

Cesium8

Sources

www.biography.com/people/john-dalton-9265201www.famousscientists.org/john-dalton/http://www.iun.edu/~cpanhd/C101webnotes/composition/dalton.htmlhttp://www.universetoday.com/38169/john-daltons-atomic-model/https://www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/atoms-molecules-and-ions-2/history-of-atomic-structure-32/john-dalton-and-atomic-theory-197-6138/

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