The law of conservation of mass states that:

The law of conservation of mass states that: matter cannot be created or destroyed. Only changed in form.

Who was responsible for the Gold Foil Experiment Who was responsible for the Gold Foil Experiment? What where the results of the experiment? What did he conclude based on his results?

Ernest Rutherford.

The results were: most of the radiation passed through with little deflection a small portion was deflected at wide angles, including back at the source of the radiation.

He concluded that the atom contain a small positive center called the nucleus, which accounted for most of the mass of the atom (because of _________.) He also determined that most of the volume of an atom was empty space. (because of _______________.)

How many protons does the following atom have?

31 Protons Because………..

The atomic number, which is the number of protons, is 31 Mass Number Atomic Number

Which model of the atom did John Dalton create?

John Dalton was responsible for the “marble” model of the atom John Dalton was responsible for the “marble” model of the atom. A solid, neutral, indivisible sphere.

What are the main flaws with Dalton’s model of the atom?

1. A) He thought atoms were indivisible, proven later to be divisible (into____.) B) Also, thought the atom was solid. Later proven that the volume is mostly empty space.(by……) C) Thought atoms were neutral, actually “net neutral” which means…..

2. Thought all atoms of an element were identical to each other 2. Thought all atoms of an element were identical to each other. There are ______ of all elements.

What distinguishes isotopes of an element from one another?

The number of neutrons (which helps determine the _____________) distinguishes one isotope from another.

Write the complete nuclear symbol for potassium ion with a +1 charge.

How many neutrons and electrons in this potassium ion?

20 neutrons 18 electrons

Calculate the average atomic mass of an element with the following isotopes: Element – 127 (67.02%) Element – 128 (25.67%) Element – 129 (7.31%)

127.41 amu 127 x .6702 = 85.12 128 x .2567 = 32.86 129 x .0731 = 9.43 85.12 + 32.86 + 9.43 = 127.41amu

Who was. responsible for the plum pudding model Who was responsible for the plum pudding model? What experiment did he use to arrive at this model?

JJ Thomson completed the cathode ray tube experiment.

What experimental results led Thomson to believe that Dalton’s model was incorrect?

He found that he could predictably alter the course of the cathode ray using magnetic and electric fields. The ray acted as a stream of negatively charged particles that were present in all substances.

Describe the Plum Pudding Model.

The plum Pudding model has negative electrons scattered evenly throughout a positive mass.

What was Max Planck’s view on energy? How was this different from the previous view? Who help prove Planck’s idea? How?

Suggested that energy could only be absorbed or emitted in pieces of certain size. (A quantum amount) Energy was thought to be continuous. Einstein used his idea to explain the Photoelectric effect.

Explain the photoelectric effect.

In the photoelectric effect, electrons are ejected from a metal surface when light with a certain minimum energy (or frequency) strikes the surface of the metal. If the light did not have the correct energy (frequency) no effect was noticed.

What was Bohr’s model? How was it different from Rutherford’s model?

Bohr solar system model suggested that the electrons were quantized, and therefore where only allowed certain orbits corresponding to certain energies around the nucleus of the atom. Rutherford’s model just had one general orbit for the electrons around the nucleus.

Based on the Bohr model of the atom, explain what happens to produced the yellow flame when sodium chloride is put into the Bunsen burner flame.

When the electron absorbs a quantum amount of energy, it “jumps” to a higher less stable energy level (excited state). If a lower level is open, the electron will release a photon of light with a quantum amount of energy, and fall back to a lower more stable energy state (ground state). These release photons are the source of the color produced in the flame.

Write the : orbital diagram for beryllium electron configuration for iron noble gas notation for platinum

Be=1s __ 2s __ Fe=1s2 2s2 2p6 3s2 3p6 4s2 3d6 Pt= [Xe] 6s2 4f14 5d8

What are the quantum numbers that describe the last electron in the following and identify the element (by name if possible) it describes: 4f8 2p3 1s1 5d8

4f8 2p3 1s1 5d8 n= 4 2 1 5 l= 3 1 0 2 m= -3 +1 0 0 ms= -1/2 +1/2 +1/2 -1/2 Tb nitrogen hydrogen platinum

If the first QN=3, what are the possible values of the 2nd QN? How many orbitals exist on the 3rd energy level? How many electrons? If l=3: what type of orbital? What are the possible values of the 3rd QN?

2nd QN (l)= 2 or 1 or 0 (n-1) to 0 3rd energy level has 9 orbitals (#orbitals =n2) has 18 electrons (#e- = 2n2) In a f-orbital, and the 3rd QN may be -3, -2, -1, 0, +1, +2, or +3. (-l to +l)