CHEMISTRY 101 CHP 2

1. group 1A. 2. group 2A. 3.group 7A. 4. Group 8A

.Label these groups of the periodic table. 1. Alkali metals, 2.Alkaline metals, 3.Halogens and 4.Noble gases

He

1s2 same as

Ne

1s22s22p6 same as

Ar

1s22s22p63s23p6 same as

Sublevels in each energy level

1st energy level has one sublevel: 1s 2nd level has 2 sublevels: 2s and 2p 3rd level has 3 sublevels: 3s, 3p, and 3d 4th level has 4 sublevels: 4s, 4p, 4d, 4f

10 electrons

Al+3

Electron Configurations

An electron configuration shows what levels and sublevels are full or partially full of electrons. Each configuration has several terms each in this arrangement: 4s sublevel starts filling up before 3d Potassium (19) 1s22s22p63s23p64s1 Calcium 1s22s22p63s23p64s2 Then for Sc which sublevel would start filling? 3d

Excited

An element's atoms when they become ___ , gain energy

Electron configurations of Ions

An ion has gained or lost electrons Its configuration then is like the neutral element that has the same number of electrons Example: Mg+2 It has 10 electrons Configuration 1s22s22p6 same as Neon

Valence level 1s22s22p63s23p6 1s22s22p63s23p64s1

Argon: (18 e-) Potassium: (19 e-)

Electron Configurations

At their ground state, electrons "live" in principal energy levels (shells) Called "n" and numbered 1, 2, 3,... Each principal level is divided into one or more sublevels Sublevels are named s, p, d and f s sublevel can hold up to 2 electrons p can hold up to 6 d can hold up to 10 f can hold up to 14

Electromagnetic Radiation and Color

Atoms absorb light when the difference in energy levels corresponds to a wavelength that our eyes can detect and send to our brain. This is the reason why anything has color to us!

The Octet Rule

Atoms tend to gain, lose, or share electrons until they have eight valence electrons. This fills the valence shell and gives the atom the stability of the noble gases.

Aufbau Sequence

Aufbau means "building up". Build up the energy levels, filling each sublevel in succession by energy.

write configuration

B 1s22s22p1 P 1s22s22p63s23p3 Ne 1s22s22p6 V 1s22s22p63s23p64s23d3 Zn 1s22s22p63s23p64s23d10 Br 1s22s22p63s23p64s23d104p5

Electrons "orbit" the nucleus like planets orbiting the sun Electrons and nucleus held together by force of attraction between opposite charges Energy is related to distance of electron from the nucleus

Bohr model early1900

1. Fr, Te, Ge 2. Os, Y, 3. U. Pr

Classify each element as a representative element, transition metal, or inner-transition metal. Representative element 1. (main-group element)2. Transition metal 3.Inner-transition metal (lanthanide/actinide series) Fr, Te, Ge, Os, Y, U. Pr

1. Sn, Bi, Ga 2. Sb, Ge 3. Se, Kr

Classify each of the elements as 1.metals, 2. semimetals, or 3.nonmetals Sn, Bi, Ga, Sb, Ge, Se, Kr

A +3 B. 0 C -3 D. 1

Determine the overall charge on particles with the subatomic makeups given. A. 13 protons, 14 neutrons, and 10 electrons B. 8 protons, 10 neutrons, and 8 electrons C. 15 protons, 18 neutrons, and 18 electrons D. 3 protons, 3 neutrons, and 2 electrons

Quantum Mechanics

Each shape is an Orbital ("electron cloud") Region in space where there is greatest probability of finding an electron

Orbital

Each sublevel has one or more orbitals One orbital can hold up to 2 electrons. s = 1 orbital 2 electrons spherep = 3 orbitals 6 electrons dumbbelld = 5 orbitals 10 electrons cloverleaf-ishf = 7 orbitals 14 electrons combinations

Energy

Electromagnetic radiation Is a form of ___

orbital diagram

Electron Configuration of Oxygen (8 electrons) 1s2 2s2 2p4 Orbital Diagram of Oxygen

Energy in different levels

Electrons occupy the lowest available energy levels. This is called the ground state.

configuration using the periodic table

Everything up to the last term in an electron configuration is the same So if you know the last term, you have it. The period = the principal energy level Except for "d" terms which are one level back And "f" terms which are two levels back Noble gases end in "n"p6

configuration

Example Tungsten (74) Full: 1s22s22p63s23p64s23d10 4p65s24d105p66s24f145d4 Abbreviated: [Xe] 6s2 4f145d4 Uranium U (92) abbreviated Can we make this easier than doing the whole thing before abbreviating?

set 1 C, B set 2 G, F, E

For each set of atoms, identify the isotopes. Set 1: 14/6A 14/7B 15/7C 15/8D Select the isotopes. Set 2: 20/10E 21/10F 22/10G 23/11H Select the isotopes.

Ag, Ne, C

Give the symbol for each of these elements. silver: neon: carbon:

85, 27

How many protons are in an ion with 86 electrons and a −1 charge? number of protons: How many total electrons are in a Cu2+ ion? number of electrons: Solved

1. 19 2. 19 3. 24

How many protons, neutrons, and electrons are there in a neutral atom of 43K (potassium-43)? 1. protons: 2. electrons: 3. neutrons:

1. C 2. Hg. 3.S

Identify these elements based on their locations in the periodic table. Give the symbol, not the name. 1.period 2, group 14 (4A) 2. period 6, group 12 (2B) 3. period 3, group 16 (6A)

Hund's Rule

If empty orbitals of the same energy are available, electrons singly occupy orbitals rather than pairing together. "Empty Bus Seat Rule

An atom's mass is concentrated in a small volume. This area deflects the positive particles more than 90°. Scroll Ans D

In 1904, the English physicist J.J. Thomson proposed the model of the atom commonly called the plum pudding model. In his model, negatively charged electrons, the "plums," float in a cloud of evenly distributed positive charges, the "pudding." The result is an atom with a zero electrical charge, or a neutral atom. In 1911, one of Thomson's former students, Ernest Rutherford, published evidence that disproved the plum pudding model. In a series of tests, Rutherford fired a beam of heavy, positively charged particles at very thin metal foil; he famously used gold, as shown in the diagram. It was expected that all the positively charged particles would pass through the foil, with some being deflected slightly. However, the results supported a different model of the atom. What property of atoms does this experiment demonstrate? The electrons of the gold atoms repel the positively charged particles, deflecting them. There are few atoms in a thin sheet of metal. Most of the particles pass through without being deflected. The electron cloud is dense. Its density and charge result in the deflection of positively charged particles. An atom's mass is concentrated in a small volume. This area deflects the positive particles more than 90°.

most of the atom's mass but very little of its size.

In 1911, Hans Geiger and Ernest Marsden, working under Ernest Rutherford, conducted an experiment involving alpha particles and gold foil that led to the discovery of the nucleus in atoms. The nucleus of an atom accounts for 1. most of the size and mass of the atom. 2. very little of the size and mass of the atom. 3. most of the atom's size but very little of its mass. 4. most of the atom's mass but very little of its size.

According to chemical and physical properties

In the periodic table, how are the elements grouped? randomly according to chemical and physical properties alphabetically in order of discovery

Problems with the Bohr/shell model

It only worked for H atom It did not account for repulsions between electrons. Electrons repel each other so they tend to spread apart.

Photon

It travels through space sometimes acting as a wave and sometimes as a particle of energy called a ___

2 electrons

Li+ 1s22s22p6 same as Ne

Electromagnetic

Light, which is also known as ___ radiation,

Distance of orbit proportional to energy

Minimum energy called ground state So they do not crash into the nucleus Higher energy levels are called excited states The farther the energy level is from the nucleus, the higher its energy

Pauli Exclusion Principle

No more than two electrons can occupy an orbital If there are two electrons in an orbital, the spins of the electrons are paired (opposite

Quantized vs. Continuous

Only specific energy of the electrons are possible, corresponding to the energy of the light. The atom's energy is said to be quantized.

18 electrons

S-2

Calculate electron configuration

Scandium (21) 1s22s22p63s23p64s23d1 Iron (26) 1s22s22p63s23p64s23d6 Germanium (Ge 32) 1s22s22p63s23p64s23d104p2 Barium (56) 1s22s22p63s23p64s23d104p65s24d105p66s2

Lower

The ___ the energy

26, 56, 16, 36

The chemical symbol of several elements are given. Determine the atomic number of each element. Fe Ba S Kr

K,Fe, Te, Kr,

The chemical symbols of several elements are provided. Give the corresponding name of the element. Spelling counts. Potassium Iron Tellurium Krypton

valence level:

The highest occupied electron energy level Up to 8 electrons in valence level

Wavelength

The larger the value of λ, which represents the ___ Wavelength Then release it in a characteristic unique __ spectrum

Na, Mg, Fe, I

The numbers of protons in the nucleus of four different atoms are given. Identify which element is indicated by the number of protons for each one. Enter the chemical symbol, not the chemical name. 11 protons: Na 12 protons: Mg 26 protons: Fe 53 protons: I

GROUP, PERIOD, PERIOD, GROUP

The statements either define or are closely related to the terms period or group. Match the terms to the appropriate statements. This is a vertical arrangement of elements in the periodic table. This is a horizontal arrangement of elements in the periodic table. Element 19 begins this arrangement in the periodic table. Element 9 begins this arrangement in the periodic table.

spectrum

Then release it in a characteristic unique __

PERIOD

This is a horizontal arrangement of elements in the periodic table.

GROUP

This is a vertical arrangement of elements in the periodic table.

light as a wave Light as a stream of photons (packet of energy)

Two models of light

Valence electrons

Valence electrons are in the outermost s and p orbitals They are the only electrons involved in bonding.

Bohr model

When atom gains energy, electron "jumps" to a higher energy level Also called quantum level when atom loses energy, electron "drops" to a lower energy level

Flame Tests

When ionic compounds are heated, the heat of the flame provides enough energy to excite an electron to a higher level. Then the light is emitted when the electron falls back to ground state

the number of protons

Which of the choices is the unique, defining property of atoms of a particular element? the number of protons plus the number of neutrons the number of neutrons the number of electrons the number of protons