Previously we learned that the average human body has 10,000,000,000,000 (10 Trillion) cells Q: How...
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Transcript of Previously we learned that the average human body has 10,000,000,000,000 (10 Trillion) cells Q: How...
Previously we learned that the average human body has 10,000,000,000,000 (10 Trillion) cells
Q: How many atoms are in one cell?
A: 200,000,000,000,000
100 x more than there are stars in the milky way
2,000,000,000,000,000,000,000,000 200 septillion atoms in the body
Crash Course History of Atomic Structure
The term matter describes all of the physical substances around
us: your table, your body, a pencil, water, and so forth
Anything that has mass and takes up space (has volume)
Made up of different kinds of atoms
Includes all things that can be seen, tasted, smelled, or touched
Does not include heat, sound, or light
Models are often used for things that are too small or too large to be observed or
that are too difficult to be understood easily
In the case of atoms, scientists use large models to explain something that is very small
Models of the atom were used to explain data or facts that were gathered experimentally.
So, these models are also theories
Universe was made of empty space and tiny bits of stuff
Called these tiny bits of stuff atomos
Atomos could not be divided
All elements are composed of indivisible particles (atoms).
Atoms of the same element are the same Atoms of different elements are different. Compounds consisted of atoms of
different elements combined together
Mostly empty space
Small, positive nucleus
Contained protons Negative electrons
scattered around the outside
Used an electric current to learn more about atoms
Noticed “electrons” were attracted to a positive end
Sometimes called the wave model
Spherical cloud of varying density
Varying density shows where an electron is more or less likely to be
Nucleus ◦Protons◦Neutrons
Electrons
Electrons Tiny, very light particles Have a negative electrical charge (-) Move around the outside of the nucleus
Protons Much larger and heavier than electrons Protons have a positive charge (+) Located in the nucleus of the atom
Neutrons Large and heavy like protons Neutrons have no electrical charge Located in the nucleus of the atom
Atomic Number = number of protons
In a neutral atom, the # of protons = the # of electrons
Atomic Mass Number - equal to the number of protons plus neutrons.
Atomic Number: number of protons in an element◦ Zr=40 protons…and
_______electrons
Mass Number: Protons + neutrons◦ H= 1 mass #◦ He=4 mass #