Term
4.1
Who first proposed that matter is made up of small, indivisible particles called atoms? Why was it unacceptable? |
|
Definition
| Democritus; he didn't explain the chemical behavior, nor did he base his theory on the scientific method |
|
|
Term
4.1
Who made the first accepted theory about atoms and what did he believe them to look like? |
|
Definition
| John Dalton; he thought they were tiny, solid, indestructable spheres |
|
|
Term
4.1
What was Dalton's atomic theory? Identify the parts that were false and why. |
|
Definition
1. All elements are composed of tiny indivisible particles called atoms. - FALSE: He failed to recognize subatomic particles.
2. Atoms of the same element are identical. The atoms of any one element are different from those of any other element. - FALSE: Not all atoms, even if they are for one element, weigh the same because they have different isotopes.
3. Atoms of different elements can physically mix together or chemically combine in simple whole number ratios to form compounds. -TRUE: An example of this would be H2O
4. Chemical reactions occur when atoms are rearranged. Atoms of one element, however, are never changed into atoms of another element as a result of chemical reaction. TRUE- An example would be 2H2 + O2 = 2H2O. Only nuclear reactions would change the element.
1803 |
|
|
Term
4.1
What was JJ thomson's discovery? |
|
Definition
He discovered the electron and pictured it as electrons embeded in the solid sphere with a positive charge throughout.
1897 |
|
|
Term
4.1
What was Hantaro Nagaoka's discovery? |
|
Definition
He suggested a nucelus that electrons orbited like rings around saturn.
1904 |
|
|
Term
4.1
Who was Ernest Rutherford |
|
Definition
He found that an atom has a small, dense, positively charged nucleus.
1911 |
|
|
Term
|
Definition
In the Bohr Model, he said that the electron moves in a circular orbit at fixed distanced from the nucleus.
1913 |
|
|
Term
4.1
Who was Louis de Broglie |
|
Definition
He proposed that moving particles had some properties of waves
1923 |
|
|
Term
4.1
Who was Erwin Schrodinger? |
|
Definition
He developed mathermatical equations to describe the motion of electrons in atoms, which leads the the quantum mechanical model
1926 |
|
|
Term
4.1
The Quantum Mechanical Model |
|
Definition
| Says the nucleus contains the neutrons and protons in the center of an electron cloud which is a visual model of the probable locations of electrons in the atom. The probablitiy of finding an electron here is higher in the denser parts of the cloud. |
|
|
Term
|
Definition
Confirmed the existence of neutrons which have no charge.
1932 |
|
|
Term
4.1
What is the smallest particle that could no longer be divided, yet still has chemical properties of the element? |
|
Definition
|
|
Term
4.2
Who discovered the proton? |
|
Definition
|
|
Term
4.2
What subatomic particle carries a negative charge? |
|
Definition
|
|
Term
4.2
Descrive JJ Thomson's experiment & what it accomplished |
|
Definition
| He used a Cathode ray tube and he ran particles (after he pulled the electrons off an atom) and ran it through the tube. Putting magnets on either side, the ray shot toward the positive magnet, meaning the subatomic particles were negative. |
|
|
Term
4.2
What is the plum pudding theory? |
|
Definition
| JJ Thomson's idea of what the atomic model was. Looked like "plum pudding" |
|
|
Term
4.2
Electrons are a component of all atoms in all elements.
^ True / False, why? |
|
Definition
| True, because in JJ Thomsons experiment, he used many types of gasses and had the same result each time. |
|
|
Term
Particle Symbol Relative electrical charge Relative mass (Mass of proton = 1) Actual mass
Electron e- 1- 1 / 1840 9.11x10-28
Proton P+ 1+ 1 1.67x10-24
Neutron N0 0 1 1.67x10-24 |
|
Definition
|
|
Term
4.2
Explain what rutherford found in his experiment |
|
Definition
| Still thinking atoms were solid, he projected a beam at them and expected them to bounce back, but because the atoms arent solid spheres, the beam actually went through and only reflected a few. |
|
|
Term
4.3
Why are elements different? |
|
Definition
| Their atoms contain different numbers of protons. |
|
|
Term
4.3
What is the atomic number? Where is it located in shorthand notation and in a regular periodic table box? |
|
Definition
| The number of protons. Shorthand: The bottom left corner, Periodic Table Box: The top right corner |
|
|
Term
4.3
What is the atomic mass? Where is it located in shorthand notation and in a regular periodic table box? |
|
Definition
| The total number of protons and neutrons in an atom. Shorthand: The top left corner, Periodic table box: Bottom center |
|
|
Term
|
Definition
| The change in the amount of neutrons in an atom, which then effects it's mass. |
|
|
Term
4.3
Why are isotopes identically alike? |
|
Definition
| They have the same number of protons and electrons. |
|
|
Term
4.3
What is the atomic mass unit? |
|
Definition
| (AMU) is the number based off of the isotope carbon-12 that measures the mass of an atom. Grams are impractical. |
|
|
Term
4.3
What is nature abundance? |
|
Definition
| The amount each isotope appears in nature |
|
|
Term
4.3
How do you find the average atomic mass of a number? (amu) |
|
Definition
| You take each isotope and multiply it by its nature / percent abundance and then add the two together and divide the total number by 100. |
|
|
Term
4.3
How do you find the number of neutrons? |
|
Definition
| You subtract the number of protons from the atomic mass. If you round the atomic mass up, you will find the neutrons in the first isotope. If you round the atomic mass down, you will find the neutrons in the second isotope. |
|
|
Term
NOTES
In what order were the following found?
Prontons, Neutrons, Electrons. Who were the discovered by? And what are their sizes? |
|
Definition
| 2nd, 3rd, 1st. Rutherford, Chadwick, Thomson. Protons and Neutrons are = 1, the size of an electron is negligable. |
|
|
Term
NOTES
Experimental vs. Theoretical chemist |
|
Definition
| Spend years perfecting their experiments VS. Study other experiments to make theories and take credit. |
|
|
Term
NOTES
What makes any element unique? |
|
Definition
| The number of protons --> Its atomic number |
|
|
