Set 2 – Chemistry Flashcard

 

  1.Dalton

2.Thomson

3.Rutherford

4.Bohr

 

1.Dalton’s Atomic Theory

-All matter is made of atoms. Atoms are indivisible and indestructible.

-All atoms of a given element are identical in mass and properties

-Compounds are formed by a combination of two or more different kinds of atoms.

-A chemical reaction is a rearrangement of atoms

2.Plum Pudding

-An atom consists of a sphere of positive charge with negatively charged electron embedded in it,

;-The positive and the negative charges in an atom are equal in magnitude, due to which an atom is electrically neutral. It has no over all negative or positive charge.

3.

-Protons in the nucleus and the electrons orbited around the nucleus.

4.

-Electrons orbit the nucleus in orbits that have a set size and energy

-The energy of the orbit is related to its size. The lowest energy is found in the smallest orbit

-Radiation is absorbed or emitted when an electron moves from one orbit to another.

;

;

Structure of the Atom

Most-empty space.

The rest-positively charged nucleus of protons and neutrons surrounded by negatively charged electrons.

The center-nucleus

Atomic Spectra

The range of characteristic frequencies of electromagnetic radiation that are readily absorbed and emitted by an atom.

The atomic spectrum of each chemical element is unique and is largely responsible for the color of matter. Atomic spectra can also be analyzed to determine the composition of objects.

Diamagnetic v. Paramagnetic

;

diamagnetic is an element with no unpaired electrons

ex. Neon is 2s2 2p6 so it is diamagnetic

Paramagnetic is an element with unpaired electrons

ex.oxygen is 2s2 2p4(unpaired e- according to Hund’s rule)

Electron Configurations

Exceptions to Electron Configurations

Exceptions to Electron Configuration Trends

Period 4:

Period 5:

Chromium: Z:24 [Ar] 3d54s1

Niobium: Z:41 [Kr] 5s1 4d4

Copper: Z:27 [Ar] 3d104s1

Molybdenum: Z:42 [Kr] 5s1 4d5

 

Ruthenium: Z:44 [Kr] 5s1 4d7

 

Rhodium:  Z:45 [Kr] 5s1 4d8

 

Palladium: Z:46 [Kr] 4d10

 

Silver: Z:47 [Kr] 5s1 4d10

 

 

Period 6:

Period 7:

Lanthanum: Z:57 [Xe] 6s2 5d1

Actinium: Z:89 [Rn] 7s2 6d1

Cerium: Z:58 [Xe] 6s2 4f1 5d1

Thorium: Z:90 [Rn] 7s2 6d2

Gadolinium: Z:64 [Xe] 6s2 4f7 5d1

Protactium: Z:91 [Rn] 7s2 5f2 6d1

Platinum: Z:78 [Xe] 6s1 4f14 5d9

Uranium: Z:92 [Rn] 7s2 5f3 6d1

Gold: Z:79 [Xe] 6s2 4f14 5d10

Neptunium: Z:93 [Rn] 7s2 5f4 6d1

 

Curium: Z:96 [Rn] 7s2 5f2 6d1

 

Lawrencium: Z:103 [Rn] 7s2 5f14 7p1

Ionization Energy

Electronegativity

 

 

 

Ionization Energy is the energy required to remove the outermost electron from a gaseous atom.

Decreasing atomic radius is a result of the same cause of increasing ionization energy: increased nuclear charge with negligible electron shielding from samelevel electrons pulls valence electrons in more tightly, making it harder to remove them, therefore ionization energy increases as you move to the right on the periodic table.

 

Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons.

 

 

 

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