Physics chapter 2 The structure of matter

All elements are in periods or (rows) ___- ____ going horizontally & increase in atomic # from left to right.

1 - 7

Today, ____ substances or Elements have been identified: ___ - ___ are naturally occurring, and the additional ___ have been artificially produced.

118 92-98 26

The formula to find the maximum # of electrons that can fit per shell is?

2(n2) ex: The K or "1st" shell can hold up to 2 electrons: 2(1) squared = 2 note: physicists call the shell number n the principle Quantum number.

The decay of 226R #88 (Radium) by alpha emission: loses 2 units of positive charge loses 4 units of mass. what is the result?

226Ra #88 ------> 222Rn #86 (Radon) "T1/2=1620yr"

If Na (sodium) has atomic #11 and can only hold 1 electron on outer shell, how many shells does it have?

3 shells: 2 in K shell 8 in L shell 1 in M shell

Except for Hydrogen, the elements of group 1 (I), called _________ ______, that combine readily with oxygen and react violently with water.

Alkali metals (soft metals) (1 outer shell electron)

Greeks named the smallest unit of matter the "________"

Atom means a (not) + temon (cut)

_________, improved Rutherford's description of the atom in which his model of the atom was a miniature solar system in which electrons revolved around the nucleus in orbits or energy levels. which is the model we present today.

Bohr (Niels Bohr 1913) note: his atom contained a small, dense, positively charged nucleus surrounded by negatively charged electrons that revolve in fixed, well-defined orbits about the nucleus. # electrons = # of protons+

Only 1 atom , __________ has an atomic mass equal to its atomic mass #

Carbon C12 note: because Carbon 12 atom is the arbitrary standard for atomic measure

_______________ is any quantity of one type of molecule

Compound ex: atoms combine with each other to form compounds (chemical bonding)

The elements of group 7 (VII), called __________, are easily vaporized and combine with metals (Na sodium) to form water-soluble salts.

Halogens (7 outer shell electrons)

_________ _______ occurs when an electron from one atom transfers to another atom resulting in the formation of an _____ pair.

Ionic bond ion note: because opposite charges attract, the 2 ions are attracted & held to each other.

What are the electron shells starting from inner most to outer?

K, L, M, N, O, P, Q........

Good way to memorize these iso-definitions is: IsotoPe = "P" means? IsobAr = "A" means? IsotoNe = "N" means? IsoMer = "M" means?

P= "same protons" (atomic z#) A= "same Atomic mass # N= "same neutron" M= "metastable" (stable or equal)

The number of __________ determines the chemical element.

Protons

Particles that are smaller then an atom are called ____________ particles.

Subatomic

What 2 metals are used in the target of an x-ray tube?

Tungsten W #74 & Molybdenum Mo #42 (Mo is right above W)

The nucleus of the atom is very small but contains nearly ____ the mass of the atom.

all

The subscript of the elemental block is the ___________ _______.

elemental mass (relative atomic mass)

An alteration in the # of neutrons does ______ ionize an atom because the neutron is electrically neutral.

not

The atom is the smallest particle (unit) of matter that retains the___________ of the element.

properties

All elements in the same group (column) _______ chemically in a similar fashion & have similar physical properties .

react

In there normal state atoms are electrically neutral; the electric charge on the atom is ______.

zero

The orderly scheme of atomic progression from smallest to largest atom is interrupted in the ____ period. Instead of simply adding electrons to the next outer shell , electrons are added to an inner shell. The atoms associated with this phenomenon are called the _______________ elements.

4th Transitional or (transitional metals) note: even in these elements, they cannot have more than 8 electrons in there outer shells too.

No outer shell can contain more than _____ electrons.

8 note: when 8 electrons are in the outer shell, the shell is filled.

Atoms with filled outer shells lie in group ___.

8 note: group 8 which are the noble gases, and are very chemically stable. (they don't react)

All elements are arranged in ___ groups as shown in the periodic table. The only element not in a group is __________.

8 (1 "left" to 8 "right") note: group #'s correspond with the same amount of outer shell electrons. EX: elements of group 1 all have 1 outer shell electron. elements of group 2 all have 2 outer shell electrons & etc... H (Hydrogen)

Electrons are very small particles that carry one unit of negative electric charge. Their mass is only ____x 10 ____ kg

9.1 x 10 to the -31 power (kg)(kilograms)

hydrogen, oxygen, nitrogen, carbon compose more than ____ % of the human body. Water molecules make up approximately ____ % of the human body.

95% 80%

The transformation is significant because the resulting atom is not only chemically different but is also lighter by 4 amu. This radioactive decay is a much more violent process. what is this?

Alpha emission note: The alpha particle consists of 2 protons & 2 neutrons bound together (atomic mass# =4). The nucleus most be extremely unstable to emit an alpha particle, but when it does, it loses 2 units of positive charge & 4 units of mass.

This nuclear transformation results in the changing of an atom from one type of element to another.

Beta emission

An electron created in the nucleus is ejected from the nucleus with considerable kinetic energy & escapes from the atom. The result is the loss of a small quantity of mass & one unit of negative electric charge from the nucleus of the atom. simultaneously, a neutron converts to a proton. what is this?

Beta emission note: The result of beta emission therefore is to increase the atomic z# by 1 (z---> z+1), while the atomic mass # remains the same (A= constant). This nuclear transformation results in the changing of an atom from one type of element to another.

2 atoms are bonded by sharing some of the same electrons, which revolve around both nuclei. This is called a?

Covalent bond "the sharing of electrons"

__________ an English school teacher, showed that elements could be classified according to integral values of atomic mass. An element was composed of identical atoms that reacted the same way chemically.

Dalton (John Dalton) ex: All Oxygen Atoms were alike, they were very different from atoms of any other element.

The fundamental particles of an atom are the ________ , _________ & ________.

Electrons (-) Protons (+) Neutrons (neutral charge)

Each block in the periodic table represents a ____________.

Element note: symbol in the middle of the block is called the chemical symbol.

According to Dalton: The physical combination of one type of atom with another was visualized as being an _____ & ______ affair.

Eye & hook note: The size & # of the eyes & hooks were different for each element.

Atomic nuclei that have the same atomic mass # (A) but different atomic #'s (z) are called? "different elements"

Isobar ex: Sulfur-40 Z# 16, Chlorine-40 Z# 17, Argon-40 Z# 18, all have the same atomic mass # but different Z#'s

2 atoms with the same atomic #'s and same atomic mass #'s are? (exist at different energy states due to differences in the arrangement of the nucleons)

Isomer ex: butane & isobutane have the same # of carbon atoms & hydrogen atoms, so their molecular formulas are the same. However, each one has a different structural formula, which shows how the atoms are arranged.

Atoms that have the same # of neutrons but different #'s of protons are called?

Isotone ex: Boron-12 has Z# 5 & Carbon-13 has Z# 6. both have 7 neutrons (same) but different amount of protons.

Arrangment: Atomic Z# Atomic mass (A) Neutron# Isotope: ______________ _______________ ____________ Isobar: ______________ _______________ ____________ Isotone: ______________ _______________ ____________ Isomer: ______________ _______________ ____________

Isotope: same, different, different Isobar: different, same, different Isotone: different, different, same Isomer: same, same, same

how many electrons can each shell hold up to? Remember formula: 2(n2): 1st K= 2nd L= 3rd M= 4th N= 5th O= 6th P= 7th Q=

K= 2 L= 8 M= 18 N= 32 O= 50 P= 72 Q= 98

____________ , (a Russian scholar), his work resulted in the first periodic table of elements. He showed that if elements were arranged in order of increasing atomic mass, a periodic repetition of similar chemical properties occurred.

Mendeleev (Dmitri Mendeleev) note: (in his time only about 65 elements have been identified)

Group 8 (VIII) elements, called _______ ____ , are highly resistant to reaction with other elements.

Noble gases (8 outer shell electrons)

____________ _______ results in the emission of alpha particles, beta particles, and usually gamma rays.

Radioactive decay

Atoms existing in an abnormally excited state characterized by an unstable nucleus. To reach stability, atom emits energy & nuclear particles. Transforms itself into a different element/atom. This is known as?

Radioactivity

_______________ may occur naturally or may be artificially produced in particle accelerator machines. They are very unstable.

Radioisotopes. note: recall that an isotope of an element is one with the normal # of protons but varying #s of neutrons(does not have a charge) ex: Barium has 7 artificially produced radioisotopes: 127 Ba, 128 Ba, 129 Ba, 131 Ba, 133 Ba, 139 Ba & 140 Ba

_____________, disproved Thomson's model of the atom. He introduced the nuclear model, which described the atom as containing a small, dense, positively charged center surrounded by a negative cloud of electrons. He called the center of the atom the "Nucleus".

Rutherford (Ernest Rutherford 1911)

___________ concluded that electrons were an integral part of all atoms. He described the atom as looking something like a plum pudding, in which the plums represented negative electric charges (electrons and the pudding was a shapeless mass of uniform positive electrification.

Thomson (J.J. Thomson 1890s)

The area in the middle of the periodic table (between groups 2 & 3) are called __________ ________.

Transitional metals note: are superior conductors of heat & electricity ex: copper Cu #29

The superscript of the elemental block is the _________.

atomic # (Z#) is the # of protons & electrons

The # of protons + the # of neutrons in the nucleus of an atom is called the ________ _______ number.

atomic mass (A) note: Is always a whole # that is equal to the # of nucleons in the atom. (protons & neutrons "subatomic particles")

Because an atomic particle is extremely small, its mass is expressed in _______ _______ _____.

atomic mass units (amu)

________ emission occurs much more frequently than _______ emission.

beta alpha

Electrons can exist only in certain shells, which represent different electron ________ _________.

binding energies ex: K, L, M, N, O, P, Q.......etc

What holds electrons in orbit? _____________ _______ & ___________ ____________.

centripetal force & electrostatic attraction (perfect balance)

_______________ ________ results from a basic law of electricity that states that opposite charges attract one another & like charges repel. (keeps electrons in orbit).

centripetal force (center-seeking force)

The force that keeps an electron in orbit is the _______________ force.

centripetal or (center-seeking force)

arrangement of electron shells helps reveal how an atom reacts _____________, that is, how it combines with other atoms to form ______________.

chemically molecules

139Ba is a radioisotope that decays by beta emission. What will be the values of A & Z for the atom that results from this emission? recall that the result of beta emission therefore is to increase the atomic z# by 1 (z---> z+1), while the atomic mass # remains the same (A= constant). This nuclear transformation results in the changing of an atom from one type of element to another.

converted to a proton & a beta particle. neutron--->proton + beta, therefore: 139Ba #56 -----> 139La #57 (Lanthanum) z=57. thus 139La #57 is the result of the beta decay of 139Ba #56.

Oxygen & Hydrogen combine into water through __________ bonds

covalent bond ex: oxygen has 6 electrons in its outer most shell. It has room for 2 more electrons because the L-shell can hold up to 8 electrons. so in a water molecule, 2 hydrogen atoms share their single electrons with oxygen because they each only have one electron.

The strength of attachment of an electron to the nucleus is called the__________ _________ __________.

electron binding energy note: designated as E sub b. - the closer an electron is to the nucleus, the more tightly it is bound.

E sub b means?

electron binding energy note: the larger & more complex the atom, the higher is the E sub b for electrons in any given shell.

The chemical properties of an element are determined by the # & arrangement of __________.

electrons

The Atom contains mostly ________ space.....

empty

A ______ ________ is an atom existing without a full complement of outer shell electrons.

free radical ex: hydroxyl, a molecule that is one hydrogen atom short of a water molecule and thus has one bond "dangling" from the oxygen.

most radioisotopes emit ____________ _____ simultaneously with the particle emission.

gamma rays

The closer an electron is to the nucleus, the __________ its binding energy.

greater

In all except the lightest atoms the # of neutrons is always ____________ than the # of protons. The larger the atom, the _________ the abundance of neutrons _________ protons.

greater greater over ex: Na sodium #11 mass= 23 which equals to 12 neutrons over 11 protons.

The __________ the total # of electrons in a atom, the more tightly each is bound.

greater note: not all k-shell electrons of all atoms are bound with the same binding energy.

Lithium #3 Li Sodium #11 Na Potassium #19 K Rubidium #37 Rb Cesium #55 Cs Francium #87 Fr These elements are all found in group ___, which are called _______ ______.

group 1 Alkali metals

Beryllium #4 Be Magnesium #12 Mg Calcium #20 Ca Strontium #38 Sr Barium #56 Ba Radium #88 Ra These elements are all found in group ____, which are called ______ - ______ _______.

group 2 Alkaline - Earth metals

Fluorine #9 F Chlorine #17 Cl Bromine #35 Br Iodine #53 I Astatine #85 At These elements are all found in group ____, which are called ___________.

group 7 Halogen

Helium #2 He Neon #10 Ne Argon #18 Ar Krypton #36 Kr Xenon #54 Xe Radon #86 Rn These are all found in group ___, which are called ______ ____.

group 8 Noble gases

The # of electrons in the outer most shell is equal to its _________ in the periodic table. determines the valance of an atom. The # of the outermost electron shells is equal to its _________ in the periodic table.

group or (column) ex: K (potassium) is located in group 1 which means it has 1 electron in the outer most shell periods or (rows) ex: K (potassium) is located in period 4 which means it has 4 shells. with the outer most being the N shell #4

Virtually all radioisotopes are capable of transformation by beta emission, but only _________ radioisotopes are capable of alpha emission.

heavy

K-shell electrons have ________ binding energies than L-shell electrons and so forth....

higher note: because the k shell is closer to the nucleus (opposite charges attract) note: not all k-shell electrons of all atoms are bound with the same binding energy.

The Protons location? The Protons charge? The Protons amu (atomic mass unit) is? The Protons atomic mass number is? The Protons mass (kg) is? Connected to:

in the Nucleus +1 (positively charged) 1.00728 amu or 1 1 atomic mass number 1.673 x 10 -27 power (kg)(kilogram) charge & mass

The Neutrons location? The Neutrons charge? The Neutrons amu (atomic mass unit) The Neutrons atomic mass number is? The Neutrons mass (kg) is? Connected to:

in the Nucleus 0 (no charge. it is electrically neutral) 1.00867 amu or 1 1 atomic mass number 1.675 x 10 -27 power (kg)(kilogram) mass

The electrons location is? The electrons charge is? The electrons amu (atomic mass unit) is ? The electrons atomic mass number is? The electrons mass (kg) is? Connected to:

in the shells (orbitals -1 (negatively charged) 0.000549 amu or 0 0 atomic mass number 9.1 x 10 -31 power (kg)(kilograms) charge

The arrangement of electrons around the nucleus determines the manner in which atoms _________.

interact

________________ is the removal of an orbital electron from an atom

ionization ex: an x-ray interacts with a carbon atom. it transfers its energy to the orbital electron & ejects it from that atom. now an ion pair is formed. The remaining atom is now a positive ion because it contains one more positive charge than negative charge.

Because electrons of atoms with many protons are more tightly bound to the nucleus than those of small atoms, it generally takes more energy to ________ a large atom than a small atom.

ionize

If an atom has an extra electron or has had an electron removed, it is said to be ____________.

ionized

An ___________ of an element is one with the same # of protons but varying #'s of neutrons in the nucleus. which does not result in an atom having a charge.

isotope ex: Barium atomic # is 56 and the atomic mass # of its most abundant is isotope is 138. Natural barium, consists of 7 different isotopes: 130, 132, 134, 135, 136, 137 & 138. Same Z# but different amount of neutrons.....

The term __________ describes all atoms of a given element. Such atoms have different nuclear configurations but nevertheless react the same way chemically.

isotope ex:ex: Barium atomic # is 56 and the atomic mass # of its most abundant is isotope is 138. Natural barium, consists of 7 different isotopes: 130, 132, 134, 135, 136, 137 & 138. Same Z# but different amount of neutrons.....

Atoms that have the same atomic # "z" but different atomic mass #'s "A" are called ____________. which does not result in an atom having a charge.

isotopes ex: Barium atomic # is 56 and the atomic mass # of its most abundant is isotope is 138. Natural barium, consists of 7 different isotopes: 130, 132, 134, 135, 136, 137 & 138. Same Z# but different amount of neutrons.....

Atoms that have the same number of protons but differ in the number of neutrons are ______________.

isotopes note: they behave in the same way during chemical reactions. they do not have a charge...

Uranium (#92 U) is the ________ naturally occurring atom. (in earths crust)

largest

How much energy is required to ionize tungsten W#74 through removal of a K-shell electron?

minimum energy must equal E sub b or 69 KeV note: less than that, the atom cannot be ionized by removal of a k shell electron.

The smallest particle of an element is an atom: the smallest particle of a compound is a?

molecule

Atoms of various elements may combine to form structures called?

molecules ex: Na+Cl = NaCl (table salt) represents one molecule of the compound sodium chloride

Physicists call the shell number ___ the principle Quantum number

n

A _____________ atom has the same number of electrons in orbit as protons in the nucleus.

neutral note: the number of protons ultimately determines the chemical behavior of the atom. note: In their normal state atoms are electrically neutral; the electric charge on the atom is zero.

If you subtract the elemental mass from the atomic # you will get the amount of _______ in that element.

neutrons ex: Na (sodium) mass# 23 - atomic # 11 = 12 neutrons

An ionized atom is _____ electrically neutral.

not note: .....but it carries a charge equal in magnitude to the difference between the numbers of electrons and protons.

Protons & Neutrons are particles in the nucleus of an atom and are called? Both have nearly __________ times the mass of an electron.

nucleons 2000 note: the Neutron is just slightly heavier than a proton Proton mass: 1.673x10 -27 power (kg) Neutron mass: 1.675x10 -27 power (kg)

The chemical properties of the transitional elements (metals) depend on the # of electrons in the 2 ____________ most shells.

outer note: remember.... even in these elements, they cannot have more than 8 electrons in there outer shells.

What are the period & group for barium?

period 6 (it has 6 shells "up to the P shell") group 2 (2 electrons in its outer most shell)

In the neutral atom, the # of electrons equals the # of __________.

protons