The Periodic Table & Atomic Structure Unit Notes: Part I
Learning Target 1: Development of the Atomic Theory

GO TO-->Chemistry-->Unit 2: Atomic Theory-->Concept 2.5: Development of the Atomic Theory-->Explore Tab 1

Essential Question: How Did the Atomic Theory evolve from Ancient Greece to Modern Day, and Which Key Scientists Made Which Contributions?
Ancient Greek philosophers were the first to discuss atoms and matter. This became known in time as____________. Atomic theory states that matter is composed of ____________ units called atoms.
Democritus (460–370 BCE) proposed that all matter in the world consisted of invisible and indivisible corpuscles (or small particle-like objects). He called these corpuscles ______________.
John Dalton (1766–1844) is best known for his work on ________________, which came about during his development of partial pressure gas laws.
John Dalton's atomic theory had five points:
________________ of particles called atoms.
Atoms of a given element have unique properties. While atoms of the ________________are identical, atoms of ________________ elements differ in size, mass, and properties.
Atoms cannot be subdivided, ________________, or ________________.
Atoms of different elements combine in simple ratios to form chemical _________________.
During chemical reactions, atoms are combined, separated, or ________________.
Vocabulary
Law of Conservation of Mass -






Early Developments in Atomic Theory
J. J. Thomson discovered the first subatomic ________________ a little more than a century ago. He used a cathode ray tube to determine that atoms contain ________________charged particles, or electrons.
Video: Thomson's Atomic Model
Question: Why is Thompson’s model called the plum pudding model? What does it say about the negative and positive charges in an atom?






Ernest Rutherford’s Gold Foil Experiment
--considered by some to be the “Father of ________________.” He is perhaps best known for his ________________ experiment.
Rutherford directed a narrow beam of ________________ charged particles toward a thin piece of ________________.
Rutherford predicted that most particles would ________________________________. He also predicted that a few would be ________________ by the electrons in the atoms of the gold foil, but that the path of these particles ________________change much.
Some of the particles, however, were _______________ at the particle source! This proved that something larger than an electron was blocking its path through the foil.
Rutherford concluded that an atom’s _______________and its mass are concentrated in a very small area of the atom.
He believed the electrons occupied the space around the ________________, his model was called the ________________ model of the atom.
He determined the radius of the nucleus to be at least ________________ times smaller than the radius of the entire atom.
Rutherford showed that the nucleus contains positively (+) charged particles we now call ________________.
Refining the Atomic Theory
Niels Bohr, studied the changes that occurred within an atom when _______________ was added to it or removed. He found that the amounts of energy absorbed and emitted by hydrogen atoms were related to the energies of their _______________.
His theory claimed that _______________ orbit the nucleus of an atom.
The amount of energy determines the electron's _______________ from the nucleus.
When Bohr studied the light energy given off by an atom of hydrogen, he found that each electron is associated with a ________________ of energy. These are referred to as ________________.
When an electron absorbs a quantum of energy, it becomes excited and moves to a ________________ energy level, one that is ________________ from the nucleus. When the electron falls from the excited state back to its ground state, it emits energy in the form of ________________ radiation (light).
Vocabulary. Define the term below
Energy Levels -





Video: Structure of the Bohr Model
Question: What are Bohr’s 4 ‘postulates’?
1.
2.
3.
4.


Bohr’s theory gave rise to the planetary or _______________ model of the atom, because it stated that electrons orbited the atom’s nucleus in circular ___________, similar to those of planets in the solar system. Bohr’s model was later proven _______________.
Modern Quantum Theory
Today’s understanding of the atom is built on Bohr’s model. It is now believed that electrons move around the nucleus in a “_______________” instead of circular paths. Quantum theory attempts to explain the fact that energy and electrons have properties similar to particles and _______________.
Video: Electron Cloud Model
Question: Why can’t we say that electrons are in orbits?






Explain Question For Learning Target 1: How did scientists use the work of earlier scientists and the contributions of their peers to develop the atomic theory?







______________________________________________________________________________

HELP!! ILL GIVE BRAINLIEST As we've learned so far, the popular model of the solar system shifted over
time from geocentric (or Earth centered) to heliocentric (or sun centered).
What role do you think technology played in this shift?
What types of astronomical tools not available to early scientists who
supported the geocentric view helped thinkers in the 16th century and beyond
develop the heliocentric model?

student builds a simple circuit with a single resistor with resistance R and measures an electric potential difference ΔV across the resistor. Then, the student replaces the resistor with a new one of resistance 2R and keeps the electric potential difference the same. What is the current (I2) through the new circuit in terms of the original current​(I1)?              6mks
​

The power in our homes and buildings cycles at a frequency of 60Hz. If someone accidentally dropped a power line into a holding tank for frogs their muscles would immediately become stiff. This is because the high frequency stimuli is causing

Calculate the magnetic field at 2m from a straight wire carrying a current of 5 A. (K = 2 x 10 ^-7)

Galileo proved the superiority of the heliocentric theory over the geocentric theory, but given our knowledge of the universe today, there was still a major flaw in the heliocentric theory of Galileo. What was that flaw?

Sound travels on air molecules.

True

False

2. Fill in the blanks
a. Two bodies are rubbed against each other they acquire __________and _____________
charges.
b. ___________are transferred from one object to another when two objects are charged by
friction.
c. __________ is a device used to secure tall buildings from the effect of lightning
d. __________charge is obtained by plastic comb when rubbed with dry hair.
e. Lightning is __________ on huge scale

help please
the question is in the picture ​

a crane lifts a 75 kg mass at a height of 8m . calculate the gravitational potential energy gained by the mass (g= 10N)

Potential energy is





stored in a state of readiness.


conserved.


energy of motion.


not measurable.

An object has a coefficient of static friction of 0.3 and a normal force of 30 N. Find the force of static friction.

Two protons in a molecule are 4.40 10-10 m apart. Find the electric force exerted by one proton on the other.

PLEASE HELP ME, IT’S URGENT!!!

What is your hypothesis for, “what effect does parachute size have on the rate that the parachute drops?”

which of the following can cause skin cancer and which can't?

Campfire
Flashlight
Lamp
Sun
Tanning bed
fluorescent light bulbs

WILL MARK BRAINLIEST IF CORRECT. WILL GIVE 30 POINTS. PLEASE ANSWER

A construction company plans to set up business in a specific location near a river. In your own words, explain the potential impacts on the economy, environment, and water cycle.

Imagine that you have three circuit elements: a single bulb, a piece of wire, and a battery. You start by keeping these three elements separate and unconnected. You use a voltmeter to measure the voltage across each of the three elements. Then, you connect the bulb, wire, and battery together to form a complete circuit, so that the bulb lights up. You repeat the measurements you made before, using the voltmeter to measure the voltage across each element while it is in the complete circuit. For the questions below, assume that the battery and the wire are ideal.

a. Compare the voltage across the battery: a) when the battery is by itself vs b) when the battery is part of the complete circuit. Is the voltage across the battery different in these two situations, or is the voltage the same? Explain your answer.
b. Compare the voltage across the bulb: a) when the bulb is by itself vs b) when the bulb is part of the complete circuit. Is the voltage across the bulb different in these two situations, or is it the same? Explain.
c. Now compare the voltage across the piece of wire: a) when the wire is by itself vs b) when the wire is part of the complete circuit. Is the voltage across the piece of wire different in these two situations, or is it the same? Explain your answer.
d. Now consider only the situation in which the battery, wire, and bulb have been arranged to form a complete circuit in which the bulb lights up. For this situation, rank i) the voltage across the battery, ii) the voltage across the bulb, and iii) the voltage across the piece of wire, according to their absolute values, from greatest to smallest. If any are the same, or if any are zero, state that explicitly. Explain your reasoning.

Help plzzzzzz


A ball at the end of a sting is being swung around a circle at a constant speed of 1 revolution per second. Why is the ball accelerating?

The three inclines have the same height and they are all frictionless, but they have different angles. Which object will have the highest speed at the bottom of the incline

Engineers and science fiction writers have proposed designing space stations in the shape of a rotating wheel or ring, which would allow astronauts to experience a sort of artificial gravity when walking along the inner wall of the station's outer rim. (a) Imagine one such station with a diameter of 117 m, where the apparent gravity is 3.10 m/s2 at the outer rim. How fast is the station rotating in revolutions per minute

I can give you 50 points.
Freddy is participating in a pumpkin lifting contest. The 68 kg pumpkin starts at rest on the ground. If Freddy exerts a 720N force on the pumpkin, what is the acceleration of the pumpkin as he lifts it off the ground?
Draw a Force Diagram for the pumpkin. Indicate the direction of the sum of the forces.
Draw a Motion Diagram for the pumpkin. Is your motion diagram consistent with your force diagram?
Use Newton’s 2nd Law to find the pumpkin’s acceleration.

Sam, whose mass is 78 kg , stands at the top of a 11-m-high, 110-m-long snow-covered slope. His skis have a coefficient of kinetic friction on snow of 0.07. If he uses his poles to get started, then glides down, what is his speed at the bottom

Currents exist in the ocean without the need of electric fields.

True
False

What is the frequency of a wave travelling at 45.45 m/s with a wavelength of 2 m?

How/is climate change/human interaction affecting mutualism

Mass of 23.94kg and volume 2.10 cubic centimeters. Calculate the density of the copper wire in si units (ų/mm cubic)

Is water a element or compound

A hot piece of copper is placed in water in an insulated cup. What is the final
temperature of the water and copper?
(Use
me AT: + copperfcoppe, Acoppe: = 0]
m = 0.50 kg water = 4.18 kJ/kg-'c,
m.copper = 0.50 kg, Cropper = 0.386 kJ/kg-°C, Ti copper = 115°C
Tower = 22°C
O A. 30°C
B. 45°C
O C. 39°C
O D. 52°C

Which of the following is not a motivation behind taking performance enhancing drugs?
A.Having bigger, stronger muscles B.improving recovery time fir injuries C. Pumping

if the mass of the object is doubled and the speed is halved then kinetic energy will change by a factor of:
2
4
1/2
1/4

1- If a skater travels 50 miles in one hour, what is the skaters speed?

2- A biker travels 10 miles in two hours, what is his speed?

3- A driver is going 42 miles in a 15 mph school zone and is pulled over by a police officer. The speed the driver was driver is known as what type of speed?